Bosch WFK2401 - Water seeping into drum

We’ve had this washer Bosch WFK2401 for about 8 years now. It’s been working great up until 6 months ago.

After a wash, sometimes (not always) cold water seeps into the drum. A few times when we didn’t use it for a few weeks, when we opened the door, water rushed out.

I think I need to replace the cold and the hot water valves - is that right - any other parts needed?

[LIST=1]
*]Water valve - Part Number: AP2805350 made by BOSCH
*]Water valve, dual - Part Number: AP2805356 made by BOSCH
[/LIST]
Any tricks on how to open the back?

Also, we have the mtaching Bosch electric dryer stacked on top. Would I have to remove it first or can I get to the back with it in place?

Thanks for advance!