How to cold pitch dry lager yeast?

hello i am wounding when using dry lager yeast how does one cold pitching do u Re-hydrating the dry yeast an bring it down to 44f ?

I recently brewed a blonde lager (3 gallons @ 1.050) with 34/70. When I got the wort down to 56 I took the yeast out of the fridge where it was 44 and sprinkled it on. I let it set for a half hour and shook the heck out of it. After two hours I put it in my cooler @ 52. I pitched at 3:30 pm and by 7 am I had 1/3 inch of foam and a burp every 17 seconds. After a week @ 52 and 9 days @ 50 the gravity was down to 1.009 and tasted pretty good. Another 3 or 4 weeks @ 36 and I’ll bottle.