1995 Tahoe 5.7 liter 136k miles

I am replacing the a/c compressor and the accumlator due to a noisy compressor. The new GM compressor was shipped dry with no oil. I know the systems requires 8 oz of 12345923 type oil. My question is how do I get the oil in the dry system. Do I pour it directly into the compressor or do I put it in using a pressurized can when I pull the vaccum