Ok if you want the rent paid, then you can give them a "72 hour pay or quit" notice after the rent is 8 days late. So that means you can give them a notice on the 18th, giving them 72 hours to pay or move out.
If they don't pay or move, then you can file a formal eviction action in the court to get a judgment and writ that the sheriff will execute to force them to move out.
However, you can give them a 60 day notice to vacate today since they have lived there over a year and then if they didn't move out within that 60 days, pursue an eviction through the courts..
In Oregon the court proceeding is quite speedy; its main purpose is to determine whether the tenant has the legal right to keep living in the rental when the landlord wants tenant to move.
To file an eviction case, landlord must complete a complaint form, which is available from the court clerk. Landlord must give the clerk a copy of the eviction notice and pay a filing fee.
After the court clerk receives the complaint and the filing fee or deferral, he or she schedules the case for a preliminary hearing called a first appearance. The first appearance is held seven days after the tenant is sent a copy of the summons and complaint. The summons tells the tenant when the first appearance is.
The purpose of the first appearance is to determine whether the tenant has a legal right to remain in the rental. If tenant does not show up, landlord should get an order giving him or her possession of the property. If landlord does not show up, the case should be dismissed.
If the tenant loses the case and does not move by the date named by the judge, landlord can get an order directing the sheriff to enforce the court's judgment. The sheriff will post a notice at the rental unit telling the tenant to move within four days. If the tenant does not do so, the sheriff will return and remove the tenant from the premises.