Never done this before so I thought I'd check in to make sure I don't screw anything up too bad.

I have an RRA Varmint with the EOP upper. I want to replace it with a normal flat top so I can put on an extended rail to get some more eye relief. As far as removing the free-float handguard, is it as simple is just removing the gas tube, throwing the thing in a block and then using a strap wrench to remove the handguard? Does the front sight base need to be loosened and moved forward to provide enough clearance?

Any words of wisdom from those with former experience is greatly appreciated.

If you have a front sight base, you will need to remove that by removing the 2 pins.  If you only have a gas block then you will need to remove the FF handguards by twisting them off.  Then you will need to remove the gas tube by punching out the gas tube pin and pulling out the gas tube.  Next either use a FF wrench or a strap wrench to remove the FF nut/ barrel nut.  Once removed, the barrel should come off by pulling it away from the upper receiver.