I am really (but not really) surprised that no one has replied to you on this.
I think it wa probably premature for you to do a diacetyl rest so soon also especially since it's a lager...it was probably not done fermenting yet.
If you've already added the extra yeast then just let it ferment out. After the brew is done fermenting (the projected FG is reached) then it's time for the DR. In which case you would let the brew come to room temp (about 70) for a couple of days. This will allow the yeast to clean up after itself and eat up any diacetyl.
Lagers usually take longer to ferment since the temp is so low.
After that it's time to bottle/keg.