I'm going to let them know this week that I don't plan on renewing lease.

If they decide to renew/extend, you can/should accommodate them by just rolling the Purchase Option payment and rent credits forward but sign new paperwork, new floor price, new mo rent credit.Take $1 for security deposit so it is a separate transaction and security deposit not confused by a tenant with the cost of the Purchase Option contract. 

Today is Nov 10th, and he still did not send me the payment and has not responded.In July, when it was time to renew the lease, he also messed up on the renewal dates on the contract and was reluctant to get it amended with the tenant.

Sometimes you may not want to be recognized as the buyer, or you may not want to reveal that you plan to move in; especially if it means you have to non-renew a tenant. 

However, if you as the owner are moving in, that would be a valid reason, so long as you give them ample notice time -- 60 or 90 days I think, depending on how long they've occupied.As for the other tenants, if this is their first lease term and they've lived there for less than a year, you can simply give them a non-renewal 60 days in advance of the end of their lease. 

We try to do them 60-90 days BEFORE lease renewal, so we don't renew a tenant taking poor care of a property.Appears your tenants will be challenging your keeping of their SD.

I started him on a short lease of 3 months, and ended up not renewing, but lost 3 other tenants as a result. 

This looks like many things but here are some idea starters for you:- Ensuring that payments are automated for receiving rent, paying mortgage, paying utilities- Ensuring the lease version used is up to date & calendar notifications are on for renewal periods- Tenant screening process is defined and followed- Turnover process is clear and team is in place- etcIf you need a CPA suggestion, I love Samantha Kelley.

I've learned some hard lessons with tenants, so I'm totally ok with not letting her renew, but also if she's been able to pay rent with unemployment maybe it can work? 

If the tenant continues to behave this way, I would consider not renewing their lease when the time comes.