So I think this wont work on changing Ranger Combat styles.
shifting Jerkin says:
On command, the wearer of a shifting jerkin can change her appearance at will as per disguise self. If the wearer has a talents class feature (investigator talents, ninja tricks, rogue talents, or slayer talents), once per day she can spend 1 hour to swap out one talent for another for which she qualifies. She can’t swap a talent that is a prerequisites for other talents or feats she has.
So you can't swap a talent that is a prerequisite for others.
Ranger Combat Style Talent says:
The slayer selects a ranger combat style (such as archery or two-weapon combat) and gains a combat feat from the first feat list of that style. He can choose feats from his selected combat style, even if he does not have the normal prerequisites. At 6th level, he may select this talent again and add the 6th-level ranger combat feats from his chosen style to the list. At 10th level, he may select this talent again and add the 10th-level ranger combat feats from his chosen style to the list.
So you select a style. And the higher level choices are dependent on that first selection.
So while you could say use shifting jerkin to get rid of the 3 feat from ranger combat style options, you could get rid of the first or second.
And you already have a ranger combat style, you can't choose another one while you already have one.
Now all that said, as a GM I don't like to say no. I would, as a house rule, tell you that if you spend three days, and for those 3 days you lose the benefit of all 3 ranger combat style feats, and you use the power of the shifting jerkin, I would let you change out your combat style. You could already do this with the retraining rules, except retraining cost money and takes more time.
As a GM, I ignore retraining costs and if you have a chunk of down time I don't see a need to strictly enforce the time tables for retraining, at least not as long as players aren't getting excessive with it.
Had some typos in my previous post that make things less clear than I'd like.
So while you could say use shifting jerkin to get rid of the 3rd feat from ranger combat style options, you couldn't get rid of the first or second.
It's a reasonable house rule, depending on how your GM handles retraining for other characters.
If your GM makes players pay for retraining and doesn't give the group extra wealth to get them back close to wealth by level and forces the long period of downtime required by retraining they may not be open to this kind of house rule.
If they aren’t open to that type of house rule then you simply extend your time required from 3 days to 5 days… swap the 3rd combat style talent for a random talent, then swap the 2nd in the same way, and finally swap the first for a new combat style and use the next two days to swap your two random talents for the 2nd and 3rd combat style talents. No houserule required since this would he fully within the standard rules.
That's true. Trade away all of the combat style talents (in reverse order) and that effectively will allow you to choose a different combat style.