Advice on replumbing basement bath

[Lois Lane]

So I disconnected the sink, toilet, and shower in the basement bath from the under-slab leaking pipes. I have run PEX from the main household supply through the bathroom ceiling and plan to run it down the back shower wall and hook it up to the water to the rest of the house (which runs under the slab of the walk out level to the back of the house in my 1950's quad level. I know it does not completely remediate the problem, but it is what I am doing for now. The 3/4 inch pipe for hot water from the boiler does not seem to be leaking, although I am sure it is and should eventually be replaced. My question: What is the best way to reconnect water from the 3/4 PEX I have run through the bathroom ceiling, down the back of the shower wall, to the 1/2 inch old copper line to the rest of the house (as illustrated in the picture). The fact the the pipe is bent has me a little flumoxed. Can I rebend it straight out into the shower cut it and put a 90 degree elbow? Should I make a connection closer to the floor where the copper pipe is fairly straight? Should I call a plumber? Thanks for all your help!

 

[Terry]

Copper only bends once, and then it gets stiffer.
Cut halfway, give yourself some leeway on both sides. Soft copper may not be totally round, so soldering may be a bit tricky.
Bridget solder is nice to use there. Or calling a plumber may be good for that spot too.
Running PEX with an expander is fairly easy, soldering old copper, not so much.

 

[Sponsor]

 

[Lois Lane]

Thanks! So a set up like this would not be problematic, other than getting a good solder joint to the old copper? (see drawing). Should I use pex or copper or it doesn't matter?