Building an AUR package with invalid MD5Checksum

I had an annoying problem: for the simulator I use for research I needed a specific library, as the simulator uses it.
This specific library osgearth is available in the Arch Linux’s AUR, but the package maintainer put a wrong MD5 Checksum into the PKGBUILD. Let’s say we trust the maintainer and don’t believe someone tinkered with the files. What do you do?

Go to an arbitrary directory

cd ~/Download
mkdir osgearth
cd osgearth

Download the Snapshot from the AUR which should contain the PKGBUILD; extract it from the archive file.

Execute makepkg -g which downloads the files and computes the MD5 Checksums. Copy the checksum, edit the PKGBUILD and put it in there.
Now makepkg -sc, where -s installs missing dependencies, and -c cleans up afterwards.
Install the compiled package with pacman -U <package>.