no welding, just cutting........and drilling. You'll also need butyl tape and probably some bulb seal (both available at McMaster Carr). The anti-scuff roof tape is available from Sportsmobile.
You may also want to consider the cro-mo tubing mod for the crossbars.
I have a top waiting to go on my van, and I am planning on lots of photo documentation when the time comes to install, hopefully in the next few weeks.
I'm planning on using a pneumatic air chisel for most of the cutting, and using a sawsall with a metal blade for the ribs/stiffeners. The SMB cut job on the donor van looks like it was done with a chainsaw, so I'm hoping to do better.
I need to paint my top (already have the supplies), install the headliner, lights and edge seal before I cut the hole.
I also have created a drawing of the hole cut-out from the donor van, so if someone needs it, just PM. It would be great if the hole from this van is measured and documented, as it would be another data point.
The removal thread is here viewtopic.php?f=24&t=11764&hilit=popping