I've seen a lot of threads and instructions that go through the process, with this process, I never lost root or recovery, and kept the old hboot so no problems of rerooting in the future if necessary. all credit goes to the developers of the various packages.
starting at stock.
1. Unrevoked installed (root+clockwork)
1.5 Reboot into recovery and make a nandroid backup
2. Unrevoked Forever installed (S-off) *much thanks to Unrevoked
3. Download updated radio 2.15.00.07.28 *much thanks to adrynalyne
4. Copy the radio downloaded in step 3 to root of sdcard
5. reboot into hboot (power off, press volume down while pressing power, let go when it comes up)
6. choose yes to install the radio
7. reboot phone
8. Download official HTC Sense/Froyo v3.21.605.1 release (pulled from signed RUU) *much thanks to rmk40
or whatever flavor of 2.2 rom you like, (I personally use Virtuous)
9. Copy the ROM downloaded in step 8 to your sdcard
10. do a full titanium backup (much easier if you purchase it)
11. download rom manager (please donate)
12. run rom manager, choose Install ROM from SD Card, find the ROM you copied over in step 9.
13. Check both "Backup Existing ROM" (nandroid backup) and "Wipe Data and Cache"
14. Let it run.
15. When it reboots, restore your apps with titanium (be careful not to restore any 2.1 apps)
16. enjoy Froyo
benefits, you get to keep the older hboot (no real benefit to upgrading other than loosing the ability to root using unrevoked)
You never lose clockwork mod or root
you are fully up to date
starting at stock.
1. Unrevoked installed (root+clockwork)
1.5 Reboot into recovery and make a nandroid backup
2. Unrevoked Forever installed (S-off) *much thanks to Unrevoked
3. Download updated radio 2.15.00.07.28 *much thanks to adrynalyne
4. Copy the radio downloaded in step 3 to root of sdcard
5. reboot into hboot (power off, press volume down while pressing power, let go when it comes up)
6. choose yes to install the radio
7. reboot phone
8. Download official HTC Sense/Froyo v3.21.605.1 release (pulled from signed RUU) *much thanks to rmk40
or whatever flavor of 2.2 rom you like, (I personally use Virtuous)
9. Copy the ROM downloaded in step 8 to your sdcard
10. do a full titanium backup (much easier if you purchase it)
11. download rom manager (please donate)
12. run rom manager, choose Install ROM from SD Card, find the ROM you copied over in step 9.
13. Check both "Backup Existing ROM" (nandroid backup) and "Wipe Data and Cache"
14. Let it run.
15. When it reboots, restore your apps with titanium (be careful not to restore any 2.1 apps)
16. enjoy Froyo
benefits, you get to keep the older hboot (no real benefit to upgrading other than loosing the ability to root using unrevoked)
You never lose clockwork mod or root
you are fully up to date