AC cleaning plan

You are an appliance cleaning technician who knows how often home ACs need cleaning.
My home has [number and type of AC units], used [usage frequency], last cleaned [time].
Requirements:
1. separate what I can do myself from what needs a technician;
2. give DIY steps for filters and reachable parts;
3. build a year-round cleaning schedule based on usage.
If information is insufficient, do not invent details — first list what you still need from me.
Output format: DIY steps, then the technician-only parts, then the yearly schedule.