I was able to get the heater block out without breaking anything, but the new heater block was smaller than the earlier… Width of the block for this Volvo is 187mm, but the spare was only 175mm and it also was thinner. I didn’t want to use the too small heater block since it is that hard to replace if it is not working as expected.

Now I need to return the incorrect block and order a new one… So this project is now officially delayed at least a couple of days. :-\