i just did a small search, this is a very old laptop using a very old cpu socket pga478
there is not much cpus out there available for this machine, only used
on another post here on toms hardware i fount this information
http://www.tomshardware.com/answers/id-2093134/upgrading-toshiba-satellite-c655-cpu.html
that machine , fo gaming, after 5 years, well, not sure if it is worth the money to upgrade it
surely you have to disasemble the entire machine to remove fan and heatsink, the cpu is only part of the system, you still need a new gpu and i don't think it can be changed on that model
better save some money and buy a new laptop, a gaming laptop with a new gpu is what i would do