What do I need to know

My DDR 2700 two 256 Dimms are on there way will be here tomorrow,is there anything I need to know or do before I take out the 133 MHZ and add the DDR?
Or do I just put it in and turn it on?
Thanks again guys..

Just put it in. It's basically the same memory tested to run at a higher frequency. Physically there is no difference.