Weil-McLain Ultra 230 Blower Replacement

I need to replace the blower in my Weil-McLain Ultra 230 LP gas boiler. I have purchased the Ultra-230 Blower Replacement Kit (Part # 383-500-040). The blower came with replacement instructions that are, for the most part, very straightforward. However, what I did not know was that I will need to disconnect the gas line union directly below the gas valve.



My questions are, first, pipe wrenches will be the proper tools for this job so I don't damage boiler components. The instructions indicate I will need two wrenches, one to loosen the union and the second to hold the gas line securely. How does the union function so I am cranking on the right part and turning in the proper direction? Also, there looks to be some sort of pipe dope/paste. How difficult will this old dope/paste make it to loosen the union AND what is the best stuff to get to put it all back together?



Like I said, everything else is straightforward.



Thanks!

Weil-McLain Ultra 230 Blower Replacement