You have two options:

• Install pyqt5 as root. Then, as an unprivileged user, simply download, verify the gpg sig and untar the electrum tarball download and execute run_electrum in the directory that gets created. Most dependencies are included with the tarball so this is all you will have to do.

• Another option is to use the appimage version. Just make it executable and run it. It contains all dependencies. This is recommended if you don't have python 3.6 available for your distro.