You can't use small claims court for this -- patent disputes may only be heard in federal court.
Correction of inventorship is usually handled under the following statute:
"35 U.S.C. 256 Correction of named inventor.
Whenever through error a person is named in an issued patent as the inventor, or through error an inventor is not named in an issued patent and such error arose without any deceptive intention on his part, the Director may, on application of all the parties and assignees, with proof of the facts and such other requirements as may be imposed, issue a certificate correcting such error.
The error of omitting inventors or naming persons who are not inventors shall not invalidate the patent in which such error occurred if it can be corrected as provided in this section. The court before which such matter is called in question may order correction of the patent on notice and hearing of all parties concerned and the Director shall issue a certificate accordingly."
However, a correction under 35 USC 256 requires all parties to sign a new oath, so if he is unwilling to sign such an oath, you can't use these provisions.
In such a case, you could file a for a reissue application, but you would probably want to retain the services of a patent agent or attorney to go this route. However, generally you do not need to have the signature of an inventor if the purpose of the reissue is to remove the name of that inventor.
He now wants to take control over the decision I would like to make regarding the selling or openning up a business with it.
Just FYI, he can't tell you what you can or can't do with the patent:
"35 U.S.C. 262 Joint owners.
In the absence of any agreement to the contrary, each of the joint owners of a patent may make, use, offer to sell, or sell the patented invention within the United States, or import the patented invention into the United States, without the consent of and without accounting to the other owners."
Of course, you can't keep him from doing something, either.
You could try and solve this contractually, by maybe paying him some money to assign his rights to you, or something. However, if you are planning on really using this patent to protect yourself, and perhaps asserting it against someone else in the future (to stop infringing activity), then you really need to correct the inventorship. Having the inventorship wrong on a patent could cause the court to find that the patent is invalid.
See a patent agent or attorney and file for a reissue if the other "inventor" won't sign a new oath. Maybe if you can convince him the patent may be invalid unless he does sign, that will tempt him to sign...
