Also: do you need to get a priest to change the little office of our mother or can you just switch it to the daily rosary yourself?
From what I’ve been able to figure out, the Scapular Confraternity today no longer requires the Little Office, the prayer obligation is expressed in these terms:
Members are bound to set aside regularly time to be with God in prayer, frequent
participation in the Eucharist, daily recitation of one of the hours of the liturgy or of some
psalms or the rosary or other equivalent prayers.
Source:
thereseocds.org/uploads/DoctrinalStatement.pdf (p. 6)
Traditionally, however, permission from a priest was required to substitute the rosary for the little office (and it seems to me that most investitures are still drawn from traditional forms).
The 1996 rules have the advantage of being more flexible, and clearly linking the scapular to its original purpose (a sort of scaled down religious habit). But the disadvantage is they allow for so many gradations of membership (c, d, e, and f on p.2) that it can be hard to even know anymore whether you were enrolled in the Scapular Confraternity or not!
Regardless, I would say that if you were enrolled in the confraternity, then by the rules I quoted above you can pray the rosary. If you weren’t, then you are free to participate in the spirituality of the scapular to as great an extent as you desire, and of course a daily rosary is a great way to do that.
At least that’s how I interpret the latest rules I was able to find (which I was originally looking for to get clear info on which indulgences were still in force).