Once in recovery mode, go to mounts and storage, andmount everything possible (sd-ext may give an error but ignore it)
Then finally go back, then go to install zip from sdcard -> choose zip from sdcard - Choose the nemesis zip file which you choose to download
Select yes when asked
Follow the AROMA installer, it should be as easy as installing software on your computer
Choose to install stock kernel.
After installation of it is complete, go back to CWM (first make sure that everything is mounted again) and then again, flash the nemesis zip file to get back to the installer
Now choose to install the Nemesis kernel.
After installing the kernel, you are back in CWM recovery, then go to mounts and storage and again be sure to mount everything, then flash the zip file for wifi drivers fix - Click here to download.
After installation is complete, again make sure everything is mounted, flash the nemesis installer zip and then finally choose to install the nemesis rom (you may enable the reboot option once installer is finished)
After it is installed, your phone will reboot
Enjoy the rom and please post some feedback in the comments for the rest to see