Some places you really do need tous but we did the fenicular(?) railway in bergan on our own and it was a 10/15 minute walk from the ship and much cheaper but worth every penny fo the views from the top. some passengers did the flaam train by themselves as well the train station is about 100 yards from the ship,we did the organized tour but it is one you could do by yourself no trouble at all again worth doing to see the beautiful views. if you go to olden it is very small so you might well want to do a trip from there. hope you enjoy it we've just returned from there on the ventura, amazing!! if you can try and get up on deck about 5am on the days that you travel up the fjords,i know this sounds crazy but it really is worth it, really breathtaking.
I think you can still pre book tours by using cruise personaliser. You can get to cruise personalise by using this link http://www.pocruises.com/Login.axd?ReturnUrl=/Account/Home.axd
Just click on 'log directly to cruise personaliser'on the right hand side of the page. Have an enjoyable cruise. We went onboard Oceana last year a super ship.