I have two branches master (which is very old) and new.

What I want to achieve is basically to make new branch to be master.

I tried to merge, but without success. The result of the merge was still not master branch became identical to new branch.

I tried to rebase, but also without success, it was telling me, that I have some deleted files and couldn't rebase. In the end I deleted all deleted files from tracking, but still the result of rebasing was somehow wrong.