I have a few years on you and I can tell you after working on cars for 50 years you learn a few things
First, what you were able to accomplish in an hour or two your 20’s & 30’s now plan on it taking at least 2 to 3 times longer when you reach the late 50’s and 60’s.
Next, invest in tooling that takes the strain off of you and puts it on the tool(s)
Air impacts, electric impacts, 1/2 in drives, a hefty breaker bar etc.
Yes, it can get a bit costly but your body will thank you for it and it still beats forking over the big $$$ to a repair shop.
Lets face it, even with the proper tooling your still going to be crawling around on the ground, on your knees and back.
A creeper and knee pads aren’t a bad thing either.
The old sayings holds true…
“Youth is wasted on the young” and “it sucks getting old”
You do what you can to make it as easy as possible.