there are many methods to do it.
the simplest in your case is to use simple os utilities
like this.
If this doesnt fit you, we can look into other options

[b]-- let 'a' be the source file[/b]

$ cat a
4, 4/5/01 0:00:00 , ($88.53), E
8, 7/8/02 0:00:00 , ($975.52), X

[b]-- now replace all the ($ with -
-- you need to espace ( [/b]

$  cat a | tr  ($  - > a1
$ cat a1
4, 4/5/01 0:00:00 , -$88.53), E
8, 7/8/02 0:00:00 , -$975.52), X

[b]-- now remove all trailing )
-- again you need to escape )[/b]
$ cat a1 | tr -d  ) > a2
$ cat a2
4,4/5/010:00:00,-$88.53,E
8,7/8/020:00:00,-$975.52,X

quoting the man pages for tr,

DESCRIPTION
     The tr utility copies the standard  input  to  the  standard
     output with substitution or deletion of selected characters.
     The options specified and the string1 and  string2  operands
     control translations that occur while copying characters and
     single-character collating elements.

OPTIONS
     The following options are supported:

     -c    Complement the set of characters specified by string1.

     -d    Delete all occurrences of input  characters  that  are
           specified by string1.

     -s    Replace instances of repeated characters with a single
           character.

----------------------------------------------------------------------

-- now replace all the ($ with -
-- you need to espace ( 
-- syntax is
-- cat < sourcefile > | tr   find_this_pattern  replace_with_this_pattern > newFile
-- here we need to find ($ and replace with - (aiphen)
-- ( open bracelet is a reserved char. so escape it by a forward slash

$cat a | tr  ($  - > a1

-- now remove all trailing )
-- again you need to escape )
-- same here . escape closed bracket ) with a forward slash 
-- tr -d deletes the occurance of )
$ cat a1 | tr -d  ) > a2

-- let t be the source file
$ cat t
4, 4/5/01 0:00:00 , ($88.53), E 
8, 7/8/02 0:00:00 , ($975.52), X

-- strip first and third field and create a new file
-- syntax is
-- cut -f field1,fieldn -d, sourcefile > new file
-- here -d, states that, a ',' coma is the delimiter
$ cut -f 1,3 -d, t > t1
$ cat t1
4, ($88.53)
8, ($975.52)

-- to keep the first three columns and remove the forth
$ cut -f-3 -d, t > t2
$ cat t2
4, 4/5/01 0:00:00 , ($88.53)
8, 7/8/02 0:00:00 , ($975.52)

ROWS (rows per commit)
Default: To see the default value for this parameter, invoke SQL*Loader without any parameters, as described in Invoking SQL*Loader.

Conventional path loads only: ROWS specifies the number of rows in the bind array. See Bind Arrays and Conventional Path Loads.

Direct path loads only: ROWS identifies the number of rows you want to read from the datafile before a data save. The default is to read all rows and save data once at the end of the load. See Using Data Saves to Protect Against Data Loss.

Because the direct load is optimized for performance, it uses buffers that are the same size and format as the system's I/O blocks. Only full buffers are written to the database, so the value of ROWS is approximate.

SILENT (feedback mode)
When SQL*Loader begins, a header message similar to the following appears on the screen and is placed in the log file:

SQL*Loader: Release 9.2.0.1.0 - Production on Wed Feb 27 14:33:54 2002

(c) Copyright 2002 Oracle Corporation.  All rights reserved.

As SQL*Loader executes, you also see feedback messages on the screen, for example:

Commit point reached - logical record count 20

SQL*Loader may also display data error messages like the following:

Record 4: Rejected - Error on table EMP
ORA-00001: unique constraint <name> violated

You can suppress these messages by specifying SILENT with one or more values.

For example, you can suppress the header and feedback messages that normally appear on the screen with the following command-line argument:

SILENT=(HEADER, FEEDBACK)

Restrictions on Using Direct Path Loads
In addition to the general load conditions described in Conventional Path Load Versus Direct Path Load, the following conditions must be satisfied to use the direct path load method: 

Tables are not clustered. 

Tables to be loaded do not have any active transactions pending. 

To check for this condition, use the Enterprise Manager command MONITOR TABLE to find the object ID for the tables you want to load. Then use the command MONITOR LOCK to see if there are any locks on the tables. 

You cannot have SQL strings in the control file. 

The following features are not available with direct path load. 

Loading object columns 

Loading LOBs 

Loading VARRAYs 

Loading nested tables 

Specifying OIDs for object tables with system-generated OIDs 

Specifying SIDs 

Loading REF columns 

Loading BFILE columns 

Physical records (set by the command-line option READSIZE) larger than 64k