Glacier or Skylift - usually not both
Olden has no terminal building to speak of; the pier is an open area with tourist information, excursion meeting points, cafés and toilets, and everything worth doing is up the valley or along the fjord. The honest rule for a 6-8 hour call is one big thing. On a short 4-5 hour stop, pick the Loen Skylift or a village walk; save Briksdal for calls of 8 hours or more.
If a second ship is in, yours may be the one that tenders, which eats into the day before you have even started. Factor that in before booking a tight independent plan.
What Briksdal actually takes
Briksdalsbreen is about 25 km up the Oldedalen valley, roughly a 30-minute drive. From the Briksdalsbre Fjellstove the walk is about 3 km each way on a gravel path that climbs steadily past waterfalls - budget 2-3 hours on foot. The troll cars, small motorised carts, take 10-15 minutes uphill to Kleivane and leave about 500 m to walk to the glacier lake; that version runs about 1.5 hours round trip.
Set expectations: the glacier has retreated a long way, and the view is across a meltwater lake to the ice rather than a wall of it at your feet. Weather turns quickly at the head of the valley, so take a waterproof jacket even on a clear morning. Olden Adventure, a local firm, runs the Briksdal shuttle bus and a Loen Skylift shuttle for independent passengers.
Sources: adventourbegins.com, norwayexplained.com, nordfjord.no, en.loenskylift.no