Open up a command prompt and type in:
cd..
cd..
cd SDK/platform-tools (hit the enter key after each line)
Then type in:
adb shell(return)
mount(sp)-o(sp)remount,rw(sp)-t(sp)yaffs2(sp)/system(sp)/system(return)
cat(sp)/sdcard/flash_image(sp)>(sp)/system/bin/flash_image(return)
chmod(sp)755(sp)/system/bin/flash_image(return)
flash_image(sp)recovery(sp)/sdcard/vrecovery.img(return)
reboot(sp)recovery(return)
(sp)=were the spaces should be. Do not type this in.
(return)=hit the return key. Do not type this in.
6. You should now be in your recovery. To scroll use the up/down volume keys. To select an option use the camera button. The first thing(and most important) you need to do is go to the backup and restore section and select backup(this will make a backup of your current system in case you make a mistake with the ROM install).
7. Now you need to do all these things(this must be done when installing a new ROM or restoring a backup) 1.wipe cache partition. 2.wipe dalvik cache(advanced section) 3.wipe data/factory reset.Now that your rooted YOU MUST NEVER USE THE FACTORY RESET IN THE PRIVACY MENU ON THE PHONE 4.format boot,system,data,and cache 5.go to install zip from sd card 6.go to select zip from sd card,chose the ROM first. It will go thru the install procedure. When done go back to step 6. and select the gapps. When all this is done select reboot system now.
It will take 5-10min.for the initial reboot. If you installed a Gingerbread ROM You will be asked to sign in,skip this.
Now you can go to the market app and click on it and sign in to your google account(you must have your e-mail address and log in code).Reboot the phone twice then set up your apps. Once you get everything set up just the way you like it and all your apps are just where you want them,go back into your recovery and make a backup of that ROM. You can now delete the first backup if you need to (you might keep it if you ever need to revert back to stock to sell the phone).
If you want to install a theme all you have to do is go into the recovery and wipe cache partition and dalvik cache,then do the same thing you did to install the ROM(theme must remain zipped) When you need to install an update to an installed ROM,all you have to do is wipe cache,and dalvik.
To change the boot animation if you are rooted(must remain zipped) go to /system/media(make sure that you have changed permission of the system from r/o to r/w) and delete the boot animation found there. Thezn copy the boot animation you have on the sd card and paste it where the old animation used to be(on next reboot it will be there). If your not roooted use ROMTools. A very good tutorial can be found here
http://androidforums.com/optimus-v-...-custom-kernel-rom-change-boot-animation.html