if you mean you want to overclock it to 9700pro speeds then yes you will need some overclocking software to overclock your core and memory, if you just mean to make it 9700 speeds though you don't have to do anything else.
The 9500 should have the same gpu and memory clocks as the 9700, the difference is that it runs on the 128bit PCB, and only has 4 pipelines. The whole point in the mod is that it unlocks the extra 4 texture pipelines, effectively doubling your fillrate, and assuming you have the right card also utilises the full 256bit PCB of your board. Thus making it literally the same as a 9700.
Just to make sure your core and memory speeds should be at 275 / 275(550DDR) before and after the mod.
Hope this helps (and if i've made any mistakes please correct me)
You should do a search for this topic to be honest, its been discussed many times on AT.......