When I did my cams I didn't have the tensioner tool. I modified the stock tensioner to eliminate the spring temporarily and replaced it with a section of rubber tubing. You don't have to crank it down - the goal is just to take up the slack on the exhaust side of the timing chain.
'03 330i ZHP - Stock-ish
'02 330Ci - Megasquirted, E85'd and tuned by PFTuning.com