converting bachmann steam to dcc?

currently i have a bachmann n scale spectrum loco (4-8-4 norfolk and western j class #611) i bought it thinking it was dcc compatable and later found out that wasnt the case. however i am pulling my hair out trying to find a way to convert it. i allready took the engine and tender apart and if i didnt know any better i would have thought it had a decoder in it because to me it looks like one. the tender contains a rather large pc board that consumes the inside of the tender and the engine also has a pc board, much smaller though, and it plugs into the tenders board. so me it seems very complex for a standard dc loco. any suggestions would be great. thanks

The exploded parts diagram for this loco are very clear on the installation of a decoder…give it a good look.

David B