how do I replace this?

How do I replace this? is it easy to do?

also what is the part number?

tia

its not an lr part but yrm do a replacement
https://yrmit.co.uk/product/rear-body-mounting-land-rover-defender-series-23/

From memory it goes behind the rear panels either side so the body will need lifting to get it under I think.

If you are talking about replacing the full rear body member (the part in JM's hyperlink) that is a big job. As Flossie says you need to lift the rear body to replace it. That looks like an early vehicle so it might be different to the 96 plate I have.

to me it looks like a bit of painted Ali, dont think its the crossmember. but could be wrong

its certainly not an early landy, its a 2002 DCPU

I would expect the crossmember to go the whole width of the rear bed. this only goes the width of the opening, it looks like it maybe a cover for the crossmember

goldypurple said:

I would expect the crossmember to go the whole width of the rear bed. this only goes the width of the opening, it looks like it maybe a cover for the crossmember

Click to expand...

after zooming in it could be a later bodge to cover rot in the original rear body support

jamesmartin said:

after zooming in it could be a later bodge to cover rot in the original rear body support

Click to expand...

Yes, zooming in alters things somewhat.
That part should not be proud of the rear light panel evident on the left hand side. It's either a bodge or possibly the left hand side has broke away from the remainder that's behind the panel giving an illusion of something else.
Remove the bolts through it and pull it free then take another pic of what's behind.

dont think its a bodge as its the same on this landy, the piece of trim thats surround by red.

it isnt sitting proud of the light panel

goldypurple said:

it isnt sitting proud of the light panel

Click to expand...

It is the YRM part that @jamesmartin linked to in his reply.

It’s attached to the tub sides via spot welds. It Isn’t that big a job in itself, it’s the prep work to get to it that makes it a big job!

goldypurple said:

to me it looks like a bit of painted Ali, dont think its the crossmember. but could be wrong

its certainly not an early landy, its a 2002 DCPU

Click to expand...

It is a body cross member not to be confused with a chassis cross member which is the steel part your towbar is bolted to.
The body cross member is indeed painted Ali and is not available from landrover unless you purchase the whole tub that it is attached to.
On mine (1986 model) that body cross member goes behind the rear panels and also had a stiffener either end that spot welded to the lower rear wings , I've seen those stiffeners in the link that @jamesmartin gave you.
My body was off when I did mine so fairly straightforward.
If you look up underneath you may be able to see the ends of the cross member/stiffeners.
If your CHASSIS cross member looks ropey you could fit the BODY cross member easy if the chassis cross member is cut off.