NEEDED: west philly grafting help

[Park Frost]

hi fruit tree folks,

i live on n 40th st near lancaster ave. I have side yard with 4 apple trees - 2 reds / 2 greens. having these fruiting apple trees here has been great - a lot of neighbors get apples from them, and next year id like set up a system for donating apples to a horse stable. 2 of the trees are large, structurally sound, have good production - and one red & one green are tiny, spindly, always falling over, not in a place that suits them. the space would better accommodate just the 2 healthy ones, but they each need pollination. i learned a little about grafting recently & hope that maybe i can take branches from the sad small trees and graft them onto the healthier trees. however, im not skilled at grafting and havnt had success in experiments. 

i recognize it may not take / we'd have to do a number of grafts so that were likely to get one, but  expect it would go much better if someone more experienced / skilled at grafting were to help.  

im happy to discuss work / time / resource trading for the help! 

someones also welcome to take / take the unneeded cuttings off the two smaller trees (which would probably do find in a place they had adequate space / light) as ill take them down after grafting is done.

thank you!