The 6500 uses the LGA 1151 socket, so you need an i7 with the same socket (click here for a filtered shop search).
As for whether you can do it yourself, that depends how confident you feel. It's not a complicated process, but is delicate and requires care. If you are happy to do it there is a wealth of guides and videos online that will give you all the information you need to do it, and we can help you on here. If not then a local pc repair shop will do it and it wouldn't take them long at all.