Ok so there is no RUU for your Telus M8... Did you do the GPE conversion? If so, at some point I hope you had made a backup with TWRP before you did the conversion. If you did not all hope is not lost. If you didn't do the GPE conversion and you just flashed the ROM then all you'll need to do is restore a TWRP backup. Below is a link to one.
1. Download this firmware package
https://www.androidfilehost.com/?fid=24399994186368791
2. If you didn't make a TWRP backup download this backup.
https://www.androidfilehost.com/?fid=24399994186369161
Now your going to follow the direction in the OP for Returning to Sense after GPE conversion.
In step 15 instead of flashing a ROM or RUU your going to restore that TWRP back up. You'll extract that twrp backup zip onto your
sdcard/TWRP/BACKUPS/XXXXXXXXX "the XXXXXXXXX is the serial number of you M8"
That's it.
If you need more help getting back to stock then this thread should be of some value to you.
http://forum.xda-developers.com/showthread.php?t=2694297