Can you mix New and Old CV Grease?

My driver side outer boot leaked ~2-3 ounces over ~250miles from the metal band slipping off so Im trying to refill it, I went to Napa and was told that this grease can be added to the old grease ( I was very weary.....) got home and checked the back and it says to take out the original grease and use solvent to clean the old remaining grease. My question is can I mix this new grease with the standard grease without issues? I don't need the whole CV rebuild kit. Right now Im running a hose clamp to get by, also anyone know what size the smaller band is?

o and there 45,000 on the old grease

Thanks

 

You can. But I would, while you're already there, remove the old grease (as much as you can) and fill with new.