On the taxpayers profile, go to Payments then register payment. Fill in the electronic form first by selecting the tax head. Once all the mandatory fields (marked with red asterics) have been filled...
MACROS are inbuilt formulae in Excel that should be enabled once you download the return so that you can be able to fill in the details of the return. Enable MACROS under File - Options- Trust...
To make a withholding tax payment, follow the payment registration then select income tax on the tax head, select WHT under tax subhead and generate payment slip for the various transactions