Replacing 2004 D12 accessory drive and fuel pump.

Greetings. I’m getting a low fuel pressure fault and I want to change the fuel pump and accessory drive. There’s a local shop nearby that works on Volvo’s, but it will be more than a week before he can get to it. I’m thinking about tackling it myself this weekend
About how long should it take to change them?
Anyone have any tips on what to do and what not to do?
Any information you can offer will help and be greatly appreciated. Thanks

 

Thanks. Does it matter which unit is removed first?

 

I got everything tore apart today. I found some play in the drive and the pump shaft was really worn bad. Can you tell me if the pump bolt holes are open to the oil cavity? I ask this because there was like silicon sealer in the holes as if someone was sealing them from oil.