Notification to tenants of intent to sell with a twist

[Edwin Ortiz]

 Back story is: lease expired and sent tenants in advance intent to raise rent (was barely breaking) they decided to extend only 6 months at current rate. since then, i just got a job offer to move to Atlanta. I decided that since i am leaving i dont want to have to go through getting new tenants so i have decided to sell. 

"twist" is i would not mind keeping the same tenants but if they decide to leave in May as intended then I'll be behind the ball on getting it ready to sell. California law i want to give them ample notice asap.  my question is how do i formulate the letter that says if you don't renew im selling without sounding like I'm trying to handcuff them? tough situation since i have to give them so much notice but also dont want to lose time if i don't send them the letter.  they have been solid tenants for 3 years, but the business end of this is that the value of current rental rate is not value for me.