Deere makes a tool that you put in the seed holes and adjust the double eliminator to, or you can use the shank size of a 3/32 drill bit. We normally use the drill bit method, but the best option would probably to take them to someone that can run them on a stand and get them perfect.  But using the drill bit gets them pretty close where we havent had any major issues.  http://manuals.deere.com/omview/OMA89867_19/OUO6074,0000A46_19_20100714.html