I assume this is a fertility protocol. Right? That’s a huge amount of HCG for a TRT protocol.
Regardless. Add the contents of the 10mL preserved saline solution that came with the kit to the injection vial with the HCG powder. Add the saline slowly and try to aim toward the side of the bottle so as not to cause too much pressure on the powder. Best to do this in small batches like 3mL at a time because there will be a build up of pressure in the vial that might cause the fluid to back up out of the puncture hole. Pull an equal volume of air out of the vial after you are done injecting the 3mL. Repeat this process twice more to bring it up to 9mL, and then add 1 mL more to bring it up to 10mL. Remember to pull out an equal volume of air with each injection.
Slowly and gently agitate the vial up an down a few times to mix the HCG. It should mix quickly. Now you have 10mL of 10,000 IU/10mL = 1000 IU/mL.
To get 2000 IU per injection (a whopping dose I might add), you need to pull up and inject 2mL, With that volume it needs to be done IM and with a needle long enough to get into the muscle. I would use a 3mL syringe with a 25G needle at least 5/8" long. Might need to go to a 1.5 inch needle. I’ve never tried to inject that large of a volume. Injecting this much 3 times per week is going to get old really fast!
Another option is to dilute the HCG with half the volume of of saline that comes with the kit (i.e., 5mL). This will result is a solution that is 2000 IU/mL and you only need to inject 1 mL. I have injected that volume with a 31G 5/16 inch insulin syringe into my quadriceps muscle without problem. Go slow on the injection.