We did this job on Neil's D3 at the weekend, along with the timing belt. It definitely preferably to do it with the exhaust cams left in, as long as you remove the exhaust cam cap at the chain end as well as all the intake caps (both of them in the pic above). This extra one allows the chain tensioner to rotate far enough to pop the intake cam out of the chain, then you can remove the tensioner.
Doing it this way means it can be done without disturbing the timing belt, which is a bonus. The passenger side tensioner is very tight on the belt backing plate, so we removed that to help since most of it was in bits already but I think it could still be done with it still in place. Also, doing one cam at a time means there is little chance of getting it wrong since the exhaust cam remaining in place and stationary gives you an absolute reference of where the intake cam should be. If the notches don't line up afterwards then its simple to see without rotating anything.
Loosening the cam caps was a challenge in some cases as the bolts were stuck, so make sure you have a sturdy T30 Torx bit (preferably several!), and clean any gunk out of the bolt heads first. We replaced all the bolts we removed, in accordance with Elsawin. 40 in total, with 3 cam caps / 6 bolts on each side remaining in place on the exhaust cam. There is no visible difference in the length of the old vs new bolts, so even though they are torqued by degrees they don't appear to have stretched. The new bolts are £1 each, and worth every penny for the peace of mind of having nice clean threads and heads to put back in, and we gave them a very light spray of WD40 to stop any galling going back in so they all torqued up perfectly.
The biggest challenge once we worked out how to get the cams out was actually getting access to the bolts at the firewall end - both for the cam covers and the passenger side rear cam cap which does both cams. There was some fairly tortuous wiggling of tools and contorted limbs to get to those!
5 hours from MRC sounds about right. We ended up at 7 elapsed, with 2-3 people working on it, thwarted slightly by the D3 engine bay managing to be even tighter than the D2, plus Neil's car has LPG so there was some extra pipework to deal with. Its not a 2-person job all the way through, but it definitely helps to have a spare pair of hands to hold the cam while it's lined up with the chain.
