(I don't concentrate in landlord/tenant law, but most of this is a "reasonableness" type of thing and you likely don't fall under the landlord tenant act.) You don't indicate how long the roommate has been gone, if you know he is permanently gone, or if he received the notice. Some of the answers to these may make a difference. The "lease" sounds like a verbal periodic lease. I will assume a month to month type of lease. Send notice for him to remove his property by a certain date to his last known address and copy it to Facebook as well as texting and voicemail under the assumption that he has vacated the residence and abandoned his property. The Pay or Quit is more to get the person out, not the property - which can be moved.
If he has not paid and has been gone for an additional full month beyond the pay or quit notice, you will likely not have issue with removing his property to another part of the house. However, you should take pictures as you go and note anything that is damaged before you move it. That will be for your own protection if he ever comes back to get it and tries to claim damages. Usually, a walk through video of the entire room is the best first evidence, with individual pictures of anything already damaged. Also take note of any damages he may have done to the room at the same time.
Please note that this response is based upon the limited information available in the question. In addition, it is not intended to create an attorney/client relationship and is offered only as general information and not as legal advice.