I finally found out how to convert the Dell DW5808 to a MC7355 as well as the DW5811 to EM7455. I mainly followed the information on this website here:
Lenovo and other manufacturers, namely Dell are starting to use the newest Quallcomm 9×30 based cellular modems. The only modem manufacturer so far is Sierra Wireless and the model is XX7455, where XX is the form factor code. We’ll be using an m.2...
I also used some good information on these websites as well:
Bought a Lenovo Branded EM7455 and wanted to test it in a Dell E5570.
I’ve tried everything mentioned here and more with no success… maybe this will help someone:
zukota.com/sierra-wireless-em74 … vo-laptop/
Do not install any drivers
Download following Driver Pack: mega.nz/#!SYcBRR5S!KLBFTWvQ3cFK … 3LsXGcc3Ng
in Device Manager find the EM7455 device which Hardware-ID ends with “&MI_03” (its the Modem Device, “MI_03” always corresponds to the AT command COM port)
Update Driver > Browse my C…
Hope this helps others as well.