I found this one, it seems fairly simple.

Tomato Paste Recipe
Basically tomato paste is tomato that has been reduced, reduced again, and then reduced some more! It's ideal to make on a cold day over the gentle heat of a coal range.

24 large tomatoes
2 teaspoons salt or to taste
olive oil
First score a cross on the bottom of each tomato using a sharp knife. Blanch the tomatoes in boiling water, then drop into ice cold water. After this the tomato peel should almost fall off. Pull the remaining peel off the tomatoes. Cut the core out and remove all the seeds. I keep the peelings for making homemade stock and the seeds for adding into stews etc. Chop the flesh and measure what you're left with which would normally be around 4 litres. Add ½ teaspoon of salt to each litre. Place the tomato and salt in a large pot and simmer over a low heat for around 1 hour, stiring often to prevent any catching and burning. Remove from the heat and press through a fine sieve or process through a food mill. Return the tomatoes to the pot and continue to cook very slowly until the paste holds its shape on a spoon, approximately 2 to 3 hours. Stir occasionally to prevent any sticking.

Spoon into hot sterilized jars, leaving 3cm (1 in) at the top. Slop on a little olive oil to cover and seal. Ensure the lids have vacuum sealed, or the paste will spoil. Alternatively you can fill and freeze ice cube trays and free flow cubes of paste in freezer bags for use later.

I can and freeze and make tomato juice from my tomatoes.

The easiest way is to freeze them. Just remove the stem, wash and throw them in a freezer bag. The skins will come off as they thaw--I like to remove them when they are partly thawed. You can use them in any cooked dish calling for tomatoes.

Here is the way I have canned tomato paste for years-
Wash, core and quater 1 peck of firm tomatoes(I like romas). Place in kettle and and heat slowly to cause juice to run. Simmer about 20 min. Put through food mill or sieve to remove seeds and skin.
Place in a jelly bag or 4 thicknesses of cheesecloth and allow to drain overnight.(I used cheese cloth and clothespins over a large tupperware container for about 3 hours.) Add salt and spices to your liking. Pack in jars, seal and process 45 min in boiling water bath. It only makes 3 pts- nice to have smaller jars,
I like to make moe at a time so that I don't have the mess twice.
Good luck