I have seen many threads asking how to do this, so here it goes.

Step 1:

Open client.JAVA and search for:
Code:
//start of moderator/admin list, 1 = mod, 2 = staff, 3 = admin
If you're using TestScape, you will see
Code:
if (playerName.equalsIgnoreCase("nvi ible"))
{
playerRights = 3;
}
Replace it with Step 2:

Step 2:

Add this:
Code:
if (playerName.equalsIgnoreCase("Sex Machine"))
{
playerRights = 2;
}
Change Sex Machine to YourAdministratorsName

Change 2 to playerRights (refer to chart below)

Code:
playerRights Chart

2 = Administrator

1 = Player Moderator

3 = Server Owner
Made by me

Remember, R-E-P-U-T-A-T-I-O-N is always appreciated...