The steps are pretty simple....
1. Download the install file from here:https://sourceforge.net/projects/lejos/ ... .8.1-beta/
You just need the file: leJOS_EV3_0.8.1-beta.tar.gz
2. Unpack it into a directory of your choice.
3. Point the eclipse plugin EV3_HOME at the directory you chose to unpack the files to.
4. Inside the above directory you will find a file called lejosimage.zip, this is the file that you need to unzip onto the Fat32 SD card. Please see the wiki for more details, you will also need to download the Oracle JRE for the EV3 and copy this to the SD card, again see the Wiki.
If you are still having problems, please tell us exactly what it is you have done, and what problems you are having.