If you do maintenance on your BMW (S1000RR in my case), this is the least expensive way I have found to reset the Service warning light. On some models, the "Service!" warning blocks the coolant temperature on the instrument panel which is very annoying. This video will walk you through the steps of resetting the warning message and light. Do not deviate from these steps or the recommended products/software or you can permanently damage your ECU! And DO NOT use cheap Chinese OBD Bluetooth adapters made for US cars, they won't work.
Credit for this DIY goes to www.s1000rrforum.com and its multiple contributors; service reset thread located here: https://www.s1000rrforum.com/forum/maintenance/224082-anyone-tried-cheap-obd2-bluetooth-wifi-adapters-motoscan-app-5.html
What you'll need:
Bluetooth OBDLink LX adapter: https://www.amazon.com/dp/B00H9S71LW/ref=cm_sw_em_r_mt_dp_U_XPi9Cb8QA9N7B
10 Pin Adapter: https://www.amazon.com/dp/B01HQSNBR2/ref=cm_sw_em_r_mt_dp_U_RRi9CbMDMEE2Y
MotoScan software: Download from store