Rear Crossmember Replacement Help Needed...

HI my fellow Landy Lover`s,I hope your all enjoying the sun??? My question is,i`m needing to change my Rear Crossmember,as it`s starting to look like Swiss Cheese,has anybody had to change theirs??? I purchased a new Crossmember with extentions,so whats the correct way to swap my old Crossmember for my new one???
I have access to a fully equipped garage,with every tool,I may need,I even have a Plasma Cutter to cut my old Crossmember out,Thanks everyone for your advice in advance,All The Best,Lee......

The hard bit is getting the new one in the same place as the old one was.
I have done my series and after unbolting the roof to windscreen, simply unbolted the rear tub leaving a couple of bolts in the seatbox. This gives enough slack to jack up the tub, remove the old one and position the new one.
You can then drop the tub and line up the tub to crossmember bolts before final cutting and tacking into position.
You can jack the tub back up then before finishing the welds and painting.

if rear tubs in place use it to realign the new one

Here is how it was done in about 3 hours with a mate to do the welding, mine is not to be trusted.
Jack back end up to get room to work underneath (or use ramps)
Disconnect all wires coming from loom through chassis to indicators etc
Remove tub to rear cross member bolts, leaving a couple in loosely for support when cutting off
Using new crossmember as a guide mark where old one is to be cut off, remembering that 'flaps' on ends of extensions will slip over chassis members.
Using angle grinder cut off old crossmember, being careful not to damage loom
Wrap loom well in tape and fasten packers to it so that it stays away from chassis when welding
Fit up new crossmember threading loom through it and fit a few of the bolts to rear tub
Tack weld all around, then finish weld in small runs using wet cloth to limit heat getting to loom
Fit remaining bolts and replace wiring

This was on a 90 with a 200tdi conversion, on td5 models the fuel tank makes life more complicated

Mines just back on the road after doing the job (spent way more than 3 hours - 3 weeks). If you are a TD5 then the worst bit is getting the fuel tank out. I reverted to this site for a lot of assistance. Basically on a TD5 the tank is dropped in from above - you can get it out from below but it is a pig of a job. My recommendation would be to bin the tank guard which bolts down from above onto the chassis drop rails, and buy for £68 from Paddock spares a nice aluminium one that bolts upwards from below ... its the only way I could face putting it back together. Also buy new bolts - chances are you'll be grinding off a good few of them - especially from the tow bar if fitted.

The advice from jimwyllie is good. I fitted min using the bolts holes to the cabin but even then ended up a few mm out (They are slots rather than holes on the top of the cross member) - those few mm made a bit of a difference when fitting the new tank guard and my tow bar which are pre-drilled to go into the 3 holes on the underside of the cross member. A little adjustment was required, but being such thick metal was no easy job.

Still worth doing yourself - I was quoted around £1000 for the job - like you got a friend to do the welding