Merge pull request into different branch
<p>I'm maintaining a legacy GitHub repo now and there is a lot of abandoned PR into old branches. For example, I work in the v3.5 branch now, and PRs are for 3.3 and older. </p>

<p>How can I effectively merge them into my new branch if they target older ones? </p>

<p>In case it's important, I'm sure there will be no conflicts.</p>

<p>I found some old questions about similar things, but I can't find any info on how to do it via GitHub. Is there still no functionality on that? Do I have to manually do it via git?</p>