You can park your car on the south side of Snæfellsnesvegur (road 51) and basically make a straight shot to the base of the mountain from there. You'll cross some boggy/marshy land, but should be able to find enough dry spots to hop across. The trail isn't always well defined as you walk up scree slope with decently sized boulders most of the way, so some slipping and poor footing is a bit of a challenge.

When heading up the mountain, stick to climber's right as you'll avoid dealing with a cliff band that way. Make sure you have a good scrambling strategy in order to avoid kicking rocks down to the rest of your party.

The bad news is that this mountain includes a false summit. You can either mount the false summit and continue down into the saddle, or you can bypass the false summit by scooting around it on the right. The summit push is a bit steep, but actually has a pretty defined trail to the peak, so it's no big deal.

I really enjoyed being on this peak near the end of the day - the lighting wasn't spectacular to capture the details of all of the surrounding landscape, but there was some serious beauty in it nonetheless.