Hi Shankuk, good question! The best place to go to for all information on EVM2 is this topic page on TechNet:
https://www.technet-21.org/en/topics/evm
In particular, the EVM Manager Guide gives instructions on how to conduct the random site selection in EVM2:
https://www.technet-21.org/en/library/main/6350
If you want to know the technical details about how the sampling is drawn (based on target population of LD facilities), you will need to refer to the EVM1 document on this - the sampling methodology between EVM1 and EVM2 has not changed. Unfortunately the WHO EPI website where this document is stored (https://www.who.int/immunization/programmes_systems/supply_chain/evm/en/index1.html) is currently unavailable and I am unable to find it in the TechNet Resource Library. Perhaps another TechNet member with a saved copy can share?
Regards, Dan