Once you turn off of Colorado hwy 9 onto dirt, your GPS will lead you to a gravel lot. At the end of that lot there's a pretty steep gravel road that heads NNW (GPS coords:  39°25'43.01"N 106° 4'11.30"W | Map Link if you want to plug that into your GPS for parking). From this lot you'll walk up the gravel road that heads NNW, unless you have a serious 4X4 vehicle. Once you're out of the thick trees you'll see some flat areas (grassy plains with some trees) for camping here | Map Link. Up the trail further is lower Crystal Lake with some camping areas nearby. PLEASE practice LNT and do NOT camp right next to water sources (100ft away at least).

The rest of the hike up to Crystal is pretty straightforward and is a bit challenging. I will note there's one tricky navigation piece. The trail has a not-so-obvious split here ( 39°26'22.10"N 106° 5'59.97"W | Map Link) and you'll need to veer RIGHT to gain the ridgeline. If you continue straight you'll find yourself near the banks of Upper Crystal Lake with no good way to reach the summit. If I remember correctly, once you're able to see Upper Crystal Lake without having veered right already, you've gone too far and should turn around to look for the split or hike north up the talus field until you regain the trail.