The only thing you will need is a professional lube or a random kitchen oil. Now go into your bathroom and find a toothbrush with a smooth handle. If it's a vibrating one use it if you want. If you don't have a smooth toothbrush buy one for like 2 bucks.
Now take some lube and put it on your finger. Now apply it your anus. Then lube up the handle of the toothbrush and insert it into your anus to a comfortable position. Then take some more lube and apply it your hand and penis.
Now masturbate however you do. Stop and go will be good because a toothbrush can double the speed you ejaculate in.
Make sure not to hurt yourself doing this. If you are not sure of something I suggest you don't try it.
A variation of this would take the hand you don't use to masturbate and lube up a finger. Make sure your nails are cut small. Insert it or two if you can and then proceed to masturbate with your other hand.