Why do you want to get a putter fitting and what do you wish to accomplish by getting a putter fitting?
Do you like a certain colour(s), surface finish, alignment markings or shaft colour?
If you don't have access to a swing-weight machine or do not even know the swingweight, then I can figure it out for you. You would need to do a a balance measurement combined with a gram scale weight of your putter. Further instructions will follow below if we need to do a calculation.
This measurement combined with knowing the total weight of you putter will enable me to calculate its swingweight. Get a rough idea of the balance point of your putter by balancing the shaft on your finger. Keep that point as a reference and cover it with a 2 inch strip of masking tape. Then measure the exact balance point from the butt end of the grip to a marked point on the masking tape when you use a system like shown in the picture.
Please try to weigh the putter to at least the nearest gram. Better if you can weigh it to the nearest tenth of a gram.