How can I completely replace a remote repo with a local repo while preserving both commit histories?

I have two separate repos:

1. A remote GitHub repo with an existing commit history, issues, and a wiki.
2. A local git repo with its own distinct commit history.

I want to replace the contents of the remote repository with those of the local repository, effectively making the remote an exact copy of the local one.

• The commit history of the remote repository should remain intact.
• The commit history of the local repository should be appended to the remote repository’s history (i.e., the remote’s latest commit should be followed by the local repository’s first commit, and so on).
• The remote repo’s issues & wiki should remain untouched.

I have not made any attempts at this as I do not want to risk losing anything.

Edit: All commits in the local repo have timestamps AFTER the most recent commit in the remote repo.

This ended up being my solution, since my files were different enough that I didn't have to resolve many merge conflicts:

Add the remote repo to the local repo:

git remote add remote-repo ../remote-repo
git fetch remote-repo
git checkout -b remote-repo-history remote-repo/main

Merge histories:

git checkout main
git merge --allow-unrelated-histories remote-repo-history
git checkout --ours .
# here I needed to first remove all my remote repo files
git add .
git commit -m "Resolved conflicts, prioritizing local files"

Check merge is successful: git log --oneline --graph --all

Then I deleted the branch and pushed:

git branch -d remote-repo-history
git remote add origin <new-remote-url>
git push -u origin main

Disclaimer that I am very unfamiliar with git and this solution is likely not elegant whatsoever but it works to fulfill all my requirements in the original post. I should also note that this is a solo project and I do not know how others would be affected. I do not recommend following this.