It was hell of a job to correct the apple trees. The previous owners didn't really prune them buy the book. Each and every one apple tree has got the rot.
This branch was not cut properly and the rot has infected the tree. It is very important to cut the branch as close to the tree as possible so the tree can heal. If the branch is left a bit long the tree will not send the sap into it and therefore it can not heal.
This branch was cut all the way to the tree and it healed nicely :) you can see how the bark grew into the cut part. That is a sign of successful healing.
I have pruned all apple trees but one. Will finish the job tomorrow. Lets hope to get a good apple season since we are planning to do much with them.