I keep reading posts about people not being able to remove their handguard pins. I have removed about 10 of these so far. I figured I would show some people how I do it. I hope this helps somebody...
1.)Here is everything I use. The big thing is a wooden board with a hole drilled in it. I also use this for firing pin retainer pins. I use a total of 2 punches. The small one is used if you get the pin halfway out and it gets stuck. 2 punches, a hammer, and the wood board w/hole is what I use.

2.)The punch on the left I bought at ACE hardware. This is probably the BEST tool to have for the job. It is VERY durable. I broke some punches in the past, So I got one of these. It isn't a punch but I use it as one(works great!) The one on the right is just a cheap punch.

3.) I hit the pin on the left side facing me(SEE PIC BELOW). Put the gas tube/handguard over the hole and whack the pin/rivet with the hammer. I usually get the pin out within one or two hits.

4.) IF the pin/rivet only comes halfway out, use the small punch to finish the job.

Then when the pins out, Switch your handguard. The only rifle I had a lot of trouble with getting the pin out was my Yugo. Thats when I bought the thicker punch and never had the problem again. I reuse the pin that I knock out. HOPEFULLY This helps someone. This is how I do it.