You just need lub and practice. Try to fist you finger by finger. Also, you can use some anesthetic cream to prevent the pain. First 3-4 times I did anal sex with anesthetic creams, the cock of my first partner was huge.

I think it takes time and patience... it need not hurt very much at all.

Here are my suggestions:

First you really need some lube (NOT Vaselene or any kind of oil... it must be KY Jelly or similar).

Lube up your finger and your ass (or better still get someone to do it for you!)

Now, work that one finger in an out... like fucking your ass with your finger... your sphincter should start to engorge with **** (like when you take a dump).

After about 5 minutes, keep it well lubed and slowly insert two fingers.... keep going in an out with those for another 5 minutes.

Your sphincter should be really soft and engorged with **** now... you should be able to put two fingers up your ass with no pain.

Now try three fingers... some more lube... it may be a bit tight at first, but the three fingers should start going in an out without much pain after about three more minutes.

Your sphincter should now be soft and pliable and engorged with ****... your ass should be like a tight cunt.

Now your ass should be ready to take the dildo, or a cock... with plenty of lube on it.

At first it will feel tight... but work it in and out... ride it... deep into your ass and it should feel great!

Fisting is a whole different game... never tried it... I figure it could cause permanent damage to your ass!

But cocks are no bigger than a big turd... just takes some time... and some lube!