Honestly, my concern here is not the abscess but the temperature. This indicates, to me, that he is dealing not only with pain but the systemic effects of bacteria in the abscess. For this, systemic antibiotics are pretty important. It is a good sign that he is eating and drinking but I fear that may stop soon.
As for draining the abscess, it is best to be done by your veterinarian but the procedure is easy enough. It requires a light sedation or local anesthetic drug in the area that you will make a cut into. You make a cut into the abscess typically in the center of the area, drain the fluid, and then use an antiseptic flush such as betadine or chlorhexidine to clean out the abscess.
As you know, cats heal quickly so keeping the abscess open is a necessity and can be done with warm compresses and removing any scabs that form of the incision that you make. Sometimes, I will place drains to keep the area open. Again, I would wait until morning and have your vet get you the antibiotics and drain the abscess.
I hope that helps, please let me know if you have any other questions.
Is 104F very high for a kitty then? Is 99F normal? I was waiting on a vet to call back till 4:30 and then I was on my way taking my kitty to him. He called just then and I found out he did not perform surgery at all. I am visiting here and not familiar. Called the hospital of his recomendation and they are fully booked but I can drop him off for them to try and fit him in. I'm concerned with the stress leaving him, the next opening is Wed 8:30 am. What do you suggest?
104 degrees is high for a cat. High end of normal is 102.5 degrees so you are in the early stages of running a fever.
Honestly, I would consider having him looked at and treated by a vet in your area. I suspect the reason he wasn't acting normal last Friday was probably due to the abscess starting to form and now you are seeing the abscess come to a head. The best part about having a vet do the work is they can give the appropriate pain medication, fluids, etc to break the fever and get him back on the right track. Also, in case there is an issue with the procedure, they will know how to deal with it.
I often have my clients leave their animals with me to "fit in" the procedure during the day. Believe it or not, cats actually do quite well in the hospital setting and he will come home feeling a thousand times better then when you dropped him off. the sooner you get him taken care of, the sooner he will be back on the track to 100%.