Best way to cleanly remove spot welds?

I've finally recently started on my stage rally SVT Focus build. The next thing I need to do is remove the old seat mounts. I know you can use the little spot weld cutters but heard they go through the panel underneath as well as break all the time and I'm trying to avoid that if possible. I'm thinking about going the grinding method but thought I'd get some input. Thanks

If you don't need the outer piece that you are removing I have seen a finger sander used to good effect.

Carbide burr in a die grinder. Some finesse required to just cut through the top panel layer. Choose burr profile to pinpoint the cut. Don't go ape E36 M3. 

Same method fasted58 mentioned but you can also use a die grinder with 3" cutting wheel or a 4" or 4-1/2" right angle grinder with cutting wheel.

Done thousands so far. This is the easy button

Failing that, I use a 1/8" drill bit to drill the first layer, then use a 5/16" bit that I resharpen with a flat end, The 5/16 will drill to the bottom of the small hole and stop.

In reply to NOHOME :

A lifetime ago, a 16 year old me drilled out a crap-ton of spot welds in the trunk of a Dodge Demon and the donor floor from a junk yard with a 3/8" drill bit and a cordless drill. Just takes time. 

Spot weld cutter

This is the standard tool for cutting spot welds,  They come in both 5/16" and 3/8"

In reply to djsilver (Forum Supporter) :

Those work if you work slow and are really, really careful. If you aren't, you'll punch right through the floorpan like I did on 8/22 spot welds in my racecar.

Thanks for all the tips y'all i think I'm going to go ahead and try carefully grinding but will probably try with a bit if its not coming out the way I want.

This is the standard tool for cutting spot [canoes]

a metal drill? Just lightly do it on top? 

In reply to greenfieldhippi :

me and dad had to remove the inner fender of our 66 ranchero the other day (battery rot). it was spot welded in. we used 1/2 in to 15/64 to remove them. worked real good. after the welds were drilled out, we used an air chisel to remove it.

In reply to djsilver (Forum Supporter) :

This a great tool and finish the work smartly..I haven't use it personally.But check a video after seeing the tool here.. It is the best tool for cutting spot welds

How long do they last , the ones I  used a few years ago  only lasted a few hours , 

Maybe you need to let them cool down !