What are the steps of evicting a tenant.

[Keng Fong]

Background : 

I have a tenant who has been renting out one of my properties in Seattle for 6 years now, he was late on rent during the pandemic and the late rent still carries now. (roughly about $10000).  Although he has been paying an extra $300 every month but it is not consistent. I am also paying for this property's utility fees.  The lease agreement expired a long time ago and I didn't renew one for a very long time.  What would be the best thing to do here? should I hire an attorney to evict him? if so, would this process be difficult?

I am open to any advice, Thank you!