In 4 years, the Pentiums will be well above 7 GHz, trust me.
Removing and installing CPUs and heatsink fans is easy, but you still have to be careful. The main thing you have to check is that there is a motherboard riser near or underneath the CPU socket for extra stablization. Secondly, make sure you have a medium sized flat-head screwdriver. This makes things much easier. Thirdly, it doesn't take much thermal compound at all to work. The literal reason for it is to cover up the microscopic blemishes in the core of the heatsink. In other words, the amount should cover the core of the CPU with a layer about paper thin. Yes, only paper thin. It's usually better to have too much than too little, however. I'm just stating that it doesn't take much at all.
-Lasereth