How can I clean the drip pan and repair pin holes to pan until I can get an ac man out here I can see that there is gunk in the pan and I took a flat heat screwdriver and got a little out but I want to see if that is OK to do and if so what do I use to open the blockage in the pvc pipe so that it will dran outside?:confused:

You can use a water hose in reverse but be careful.
You can use a wet and dry vac to try and pull the line clear.
If you have holes in the drain pan I suggest you call now for professional help. The situation will get worse and if you have a furnace under the coil the heat exchanger can also be damaged.