I use a bone saw, cut the can at the shoulder, use a pin vise from below the chassis to drill holes from the bottom up, then mount radial lead caps from above. you can glue the cans back on if you want to look original.
I can do a 3 section in about 10min tops, uses cheaper caps,keeps lead dress orig, is less confusing to future techs trying to figure out if you did it right.
I do not need to disconnect any parts from the caps terminals this way.
All that being said, I have rarely had a tv with bad can caps from the mid 60's on, and I generally will just test them, if ok, leave them. the caps are prob better than anything you will be buying today. I know there are a lot opinions about that last statement, just my personal experience with it.
replacing caps in later model sets is not an alternative to using proper diagnostics to solve problems.
If you insist on under chassis install I would recommend installing terminal strips and trying to simulate the cap leads as close as possible to the cap, I find it more time consuming to do a neat job with term strips than the before mentioned cut off the can approach.
here is my video see about min 2.30 for can caps
http://www.youtube.com/watch?v=SgSZN...=TLrn2WEmYrL2Q