Easiest way to modify MH Qual reports at the moment would be using PDF Report Builder tool that was introduced to it with MH Qual 10. I highly recommend updating software to this version as it also brings in other improvements as well.
To get started I have kept one webinar regarding MassHunter PDF report modification which also contains some practical examples. Even though examples are for MH Quant template the graphical user interface is the same for MH Qual templates as the same tool is used with both softwares. You'll find presentation recording and PDF attached to this message.
I also attached one presentation from 2013 that goes through Excel template customization if you want to keep working on these templates. And most likely the issue you are experiencing with greyed out buttons is related to Excel settings that dictate whether or not VBA macros can be run. To fix this go to File>Options>Trust Center>Trust Center Settings...>Macro Settings and add tick to "Trust access to the VBA project object model".
I added tags to this post to increase visibility.