Exgirlfriend is refusing to leave my condo we both moved out and signed a rental agreement with new tenets to move in on or near the 1st of July. How much does the eviction cost if I do it myself and how much to have a lawyer file it for me

I have no idea what an Attorney would charge. You would be responsible for filing fees. Call and ask - I never trust the Internet because costs go up and the site could be behind.

Here is some very comprehensive info - Welcome to the Clark County Courts in Las Vegas