i need to do a deep clean on my SM045.

Mike, I don't envy you the task, but here are my first thoughts, if I had to do it. I would definitely start with scraping, with a plastic paint scraper with the smoker cold to do as much as you reasonably can. Then I'd warm up the smoker for a short time and do it again. After that, you have to decide if you want to use any kind of cleaner or grease cutter (like Simple Green) or not. If not (I would choose not) based on how much crud is left, I'd use rags and water as hot as you can handle (insulated gloves), scraping again as things loosen up (maybe a stiff disposable brush). Then heat the smoker to dry everything out and then scrape again and wipe clean with more hot water-soaked rags. Repeat as necessary. Just my $.02. Good luck!

Not a pleasant task

Rather than Simple Green, and I would choose not as well, I would use Dawn detergent. Multiple rinses and finally, season the smoker as per Cookshack's instructions for new cookers.

I'd scrape out then scrub with lemon juice. Rinse, re-season, and you're back in business.