Bumper Mounting Help
 

I got some bumpers for my street stock... On the front somebody welded a bumper to the plate where you bolt on thee correct bumper. I want that one off so I can put the correct one on.... What can I use to slice through this sloppy weld? The Below pic is the sloppy weld to the mounting plate
http://img181.imageshack.us/img181/8889/006af3.jpg


On the Rear, there is just the bars left off the previous bumper... I got the drivers side one off but the very end of the frame is knocked up a slight bit so the screw is up behind the body kind of... Can I heat the crap out of it with a torch to soften the metal and try to bring it back down to level??? Or should I just put it on a frame machine and have it straightened? Or is there any other options??? In the pics below is where the rear bumper bolts up.
http://img411.imageshack.us/img411/6286/sunp0005km2.jpg

http://img184.imageshack.us/img184/9413/sunp0009lf9.jpg

Sawzall metal cuttin blade with cutting oil.

Is this a G body? (malibu, regal, etc?)