make sure your car is tip top , tyres/oil/serviced etc
then just go for it
be prepared for possible tething troubles (PCV/DV etc) and maybe stick a bit more aside just in case (clutch if you are manual etc)
If you have a really early GTI be worth checking your cam version/follower is OK too
But most cars just remap without any issues
and are all the better for it
(dont forget to consider insurance costs too!)