Detaching bottom end of rear shocks - safe?

Gabe, you are wise to ask. The shock is what holds the axle in place in a downward vertical plain. So if you remove the stock, you can jack the body way up high. But be wary of the axle (read springs, which are being relieved).

That said, just be smart with the jack and jack stands and you should be fine. I tend to start with the car low (I can actually get my big self under the car enough to loosen the lower shock bolts with minimal jacking) and then slowly jack it up (after the bolts are removed).

I'm making it sound difficult, which it isnt. But since someone else might read this in a search, I like to give fair warning about the axle issue.

It should take you less than 5 mins to disco' both shocks' lower nuts and bolts and be accessing your brake line brackets.

Good luck.