I am trying to change to coolant on my 06 SR5 V6. I drained the radiator and overflow which voided a little less than a gallon. I can't find the engine block drains for some reason. Can I just fill up the radiator/overflow with the amount I removed and do this again in a few weeks to remove more of the old coolant? Or can I run the car for a couple of minutes will that move some of the new fluid in and I can drain it again? Repeat until I use up the 2 jugs I bought from Toyota? Please help! TIA