Request: A client asked to have a custom version of the delivered Leave Balance ESS page. Specifically they want to suppress the display of three columns.
Solution: This was a simple change to the LeaveBalancesList XML file.
The original Leave Balance page looked like the following screen print:

After the custom the page looks like the following screen print.

The steps involved are:
(1) Locate C:\Nsl64\emPath\iis\html\LeaveBalancesList.xml and make a backup copy
(2) Modify C:\Nsl64\emPath\iis\html\LeaveBalancesList.xml as follows:
From:
<tr>
<th field-name="PMF_DESCRIPTION" id="hdrPmfDescription" width="20%">Type of Leave</th>
<th field-name="EPF_OPENING_BAL_HOURS_ACCRUED" id="hdrEpfOpeningBalHoursAccrued"
horizontal-align="right" width="20%">Opening Balance</th>
<th field-name="EPF_YTD_HOURS_ACCRUED" id="hdrEpfYtdHoursAccrued" horizontal-align="right" width="20%">Hours Accrued</th>
<th field-name="EPF_YTD_HOURS_PAID" id="hdrEpfYtdHoursPaid" horizontal-align="right" width="20%">Hours Used</th>
<th field-name="EPF_HOURS_AVAILABLE" id="hdrEpfHoursAvailable" horizontal-align="right" width="20%">Hours Available</th>
</tr>
To:
<tr>
<th field-name="PMF_DESCRIPTION" id="hdrPmfDescription" width="20%">Type of Leave</th>
<!--
<th field-name="EPF_OPENING_BAL_HOURS_ACCRUED" id="hdrEpfOpeningBalHoursAccrued"
horizontal-align="right" width="20%">Opening Balance</th>
<th field-name="EPF_YTD_HOURS_ACCRUED" id="hdrEpfYtdHoursAccrued" horizontal-align="right" width="20%">Hours Accrued</th>
<th field-name="EPF_YTD_HOURS_PAID" id="hdrEpfYtdHoursPaid" horizontal-align="right" width="20%">Hours Used</th>
-->
<th field-name="EPF_HOURS_AVAILABLE" id="hdrEpfHoursAvailable" horizontal-align="right" width="20%">Hours Available</th>
</tr>
(3) Delete the following cache files if they exist
C:\Nsl64\emPath\Cache\en_CA\ESS\LeaveBalancesList
C:\Nsl64\emPath\Cache\en_CA\MSS\LeaveBalancesList
C:\Nsl64\emPath\Cache\en_US\ESS\LeaveBalancesList
C:\Nsl64\emPath\Cache\en_US\MSS\LeaveBalancesList
C:\Nsl64\emPath\Cache\fr_CA\ESS\LeaveBalancesList
C:\Nsl64\emPath\Cache\fr_CA\MSS\LeaveBalancesList
(4) End your W3WP process in the task manager.
Note that a more sophisticated approach would be to rename the XML files and to create custom a C# program. This approach would prevent the change from having to be re-applied after each service pack.