[git] How to replace local branch with remote branch entirely in Git?

I'm kind of surprised no one mentioned this yet; I use it nearly every day:

git reset --hard @{u}

Basically, @{u} is just shorthand for the upstream branch that your current branch is tracking. For example, this typically equates to origin/[my-current-branch-name]. It's nice because it's branch agnostic.

Make sure to git fetch first to get the latest copy of the remote branch.