just make sure to have the car up on jack stands and put something underneath to catch the fluid and you should be good. That is how we do it and nothing gets on the ground 
Yeah, that's how I did it. Nothing got on the ground, but I did get it over the chassis. Sigh.
Anyway, given DBG's dig, I took a couple of photos of my PS reservoir tube routing (there's plenty of photos of the brace install already!). This is definitely not the only way to route these, maybe not even the best way, but it's what I did, if it helps...
First, showing the new mounting bracket in place sandwiched between the fusebox bracket and the body bracket, using the original bolt and clip nut that was there. I routed the tubes between the two arms of the fender bracket and then nice and snug between the inner arm and the wheelwell liner (arrow):
[attachment=1]
Next is taken from the inner (engine) side of the fusebox, showing the tubes, arrowed, coming out from the wheelwell area as noted above:
[attachment=2]
Lastly one taken from above showing the two tubes (smaller below and obscured by the larger) zip-tied back to the old reservoir bracket, away from the turbo (A). Then the smaller tube is zip-tied to the shock tower (B) but protected from wear by a small cutoff of the smaller tube that's been slit down its length and pushed over the metal lip:
[attachment=3]
Tip: route the tubes first and make sure all is good, before attaching either end(s) (Don't ask)