Pull down the quick settings menu, and look for the pen icon.
Tap it to enter edit mode.
Keep in mind that the first six on top are considered the main ones, they appear even when the menu is pulled partway down.
These should be your most used ones.
The rest will be listed further down, and below the active ones is a line with a note saying 'drag below to remove'.
The tiles for apps that you have installed are most likely below this line, so long press them and bring them above it.
Occasionally there may be a glitch (in my experience, with multiple devices) where a tile is way down in the bottom and it will not allow me to bring it up into the useable tile range.
If that happens, just bring up tiles above it into the useable range until the one you want is there too, then pull the undesired ones back down below the line.
Tedious, but effective.