So break out your cleaning supplies and a cold drink and let's get to work!
Step 1: Supplies
Degreaser of some sorts
Shop Vac (optional)
Cold drink (preferably Narragansett Lager for that summer in RI feeling)
Step 2: Disconnect Propane
Take a sip of your drink.
Step 3: Remove Grates and Burner Covers
Look at them and think about how nasty all that build up is. Take another sip of your drink and move onto the next step.
Step 4: Scrape and Suck
Take another sip of your drink and think about how nice it is today. Move onto the next step.