We are updating the article with more direct adjustments by Scottish and Xronos. Now using THIS flex you can directly enable Edge, Engineering and Quad-Band with few click:
1. Open Radiocom, choose GSM - Main-MA-GSM, and go to Settings-TCPIP-MLINK USB LAN Driver. Connect the phone in "Modem" mode
2. Go to "Common Applications -> Flex Programmer"
3. Choose the flex file and flash it!

That's it - you will have Quad Band phone with Engineering and EDGE enabled! Tested on 41P, 46P and 48P

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Here is the old tutorial (suitable for people who wish to know how to "do it yourself"):

This tutorial describes how to enable EDGE on Motorola ROKR E2. Thanks to Scottish and Xronos from Motofan!

1. You need to open the program Radiocom (this is copyrighted software - do not ask us where to download it! You need to buy it!)
2. Connect the phone to the computer in "Modem" mode. In Radiocom select Main-MA-GSM and then select Settings -> TCPIP -> MLINK USB LAN Driver
3. Go to Common Applications -> Flex Programmer, select this flex (this is European flex from 41p, which works on all firmwares) and press the FLEX button. During the flash you may receive errors - no worries it do not affect the firmware, so select "Ignore ALL failures"
4. Go to GSM2, open seem 0341_0001 and change FF to 01 and save it
5. Now open seem 0340_0001, set length to 0008, replace the 000...00 with 09 05 03 02 01 02 00 00 and save it
6. Open seem 02AF_0001, set length to 0002, replace 27 (could be different) to 75 and save it
7. Open seem 010A_0001, set length to 0002, replace 01 (could be different) to 03 and save it.
8. Now open seem 0032_0001, open it with XVI32 or other hex editor (check the seem editing tutorial) and change offset 0089 to 0C. Convert it back to hex string and save it on the phone back with Radiocom.
9. Disconnect and reboot the phone. Enjoy EDGE!!!