Please be VERY careful when using this method as you can brick your phone. Make sure you triple check the file you downloaded is the right size and placed in the right area, but most importantly that the command lines you type are exactly right. If you are not comfortable using this method, then please do not and go find a flashable version of these recoveries.
I've posted a procedure to format/'flash' your recovery while on your phone in one of the threads on here and was asked by a Forum Mod to make a quickie guide to be placed as a sticky on the dev boards so others might benefit.
Anyway, here is a very quick and easy way to change your ClockworkMod recovery with a couple of command lines.
The TWRP link is in the second post.
Now for the ClockworkMod Instructions:
1. First, go here and look up your ClockworkMod recovery that pertains to your phone: http://www.clockworkmod.com/rommanager
2. Download the .img file for your phone and save it on your computer.
3. Rename the .img file to recovery.img and save it to your internal sd card of your phone. For example: recovery-clockwork-126.96.36.199-hercules.img ------> recovery.img
4. Open up Terminal Emulator on your phone and type the following 2 commands:
dd if=/sdcard/recovery.img of=/dev/block/mmcblk0p22
(please note the second command is a one line command with spaces between "dd & if=" and ".img & of=")
If your Rom identifies your internal sdcard as /emmc instead of /sdcard, then make the adjustment to command line (dd if=/emmc/recovery.img) instead of what is posted above.
You can also issue these commands from adb shell if you are connected to your computer.
If Terminal Emulator does not have Superuser or SuperSU permissions for root privileges then make sure it does. You can also go from NON Touch CWM to Touch CWM using this and vice versa. Simply make sure you have the right recovery for your phone and rename it to recovery.img.
As for explanations:
dd if= command is a common Unix program whose primary purpose is the low-level copying and conversion of raw data.
dd stands for "data description"
if stands for "input file"
of stands for "output file"
the = is the location of the data you are using. ie. /sdcard/recovery.img
the /dev/block/mmcblk0p22 is the location/partition of the recovery on your phone.
So essentially you are doing a low level rewrite of the recovery image on your phone via command lines.
***Also, the best way to remember this command line is to not to. Copy the command line and save it to your own personal contact info in Google under Notes and then you will have it with you wherever you go. You really do not want to mess with getting it wrong. You could brick your phone if you mess things up.
Anyway, I hope this helps. . . . it really is very easy to execute without fault.