[Amazin]

I already purchased bullyliner so just need to know what I need to do to the surface on the back of my van before I start to apply it.
is it:

-Remove the ply/wooden boards and give a thorough clean
-use sandpaper to scuff the paint, doesn't need to be all the way down to the metal
-Clean everything again and use Acetone on the surface to remove all dust

It should be ready to paint after that right? please let me know if I missed any steps.  I don't need to use any primer or anything like that do I?

[Elfyn]

If your bullyliner is anything like Protectakote it will stick to anything. I've even painted the bottom of my hose reels where the powder coating peels off - sticks like s**t. As long as it's dry, I think you've done more than enough.

[Splash & dash]

I already purchased bullyliner so just need to know what I need to do to the surface on the back of my van before I start to apply it.
is it:

-Remove the ply/wooden boards and give a thorough clean
-use sandpaper to scuff the paint, doesn't need to be all the way down to the metal
-Clean everything again and use Acetone on the surface to remove all dust

It should be ready to paint after that right? please let me know if I missed any steps.  I don't need to use any primer or anything like that do I?

Sounds like you have covered everything but there must be instructions on surface preparation on the tin of paint ?