We have a 2011 390RB-60 and we too wrestled with the DEF filling at first, then the light came on. For approximately $25 I purchased a Flo-N-Go syphon and filling the DEF is a one person job. Once the access panel is raised the 2 1/2 gal container will sit on the panel near the hinge, protecting the paint finish with a towel, a couple of squeezes on the priming handle and the DEF flows without spills.
WIth a full DEF tank we were able to drive from Calgary to Ottawa wich is about 2500 miles on 3/4 tank of DEF. One thing to consider purchase your DEF in the USA, it is considerably less expensive than in Canada. We always leave the USA with a full tank of DEF plus a spare container, this will do us until we return to the USA.
George & Diana