There is an overflow plug on the drain pan. Takes an Allen wrench although I'm not sure which size. The fluid should barely trickle out of the overflow plug (at operating temp, fluid expands so temperature is important) when it's at the correct level. Although it's a pain without a dipstick, I'd follow
this guide. If no fluid comes out at all, there is a 24mm fill plug that you can pump fluid into. Some say you can gravity fill it but I've never had any luck with that so I use a small hand pump.
