This vesting can occur in the sacristy (as is depicted here) or also in the church itself.
John Sonnen of Orbis Catholicus captured one form of these ceremonies recently at the Solemn Pontifical Mass in Imperia.
It is quite interesting to consider some of the similiarities here between the vesting of the bishop in the tradition of the Latin West and that of the vesting of a bishop in the Byzantine rite:
The Bishop goes to the Kathedra (a raised platform with the episcopal chair) - which has been set up at the Bema (the centre of the Sanctuary). Then, in the midst of his people, he is vested by the deacons and subdeacons. The Protodeacon standing on the Ambo, prays aloud the prayers of Vesting, while 2 deacons incense. There is a wonderful ambivalence in the theology of Vesting. Actually, there are 2 sets of Vesting Prayers: those proclaimed alto voce by the Protodeacon and those said soto voce by the Bishop.
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While the Bishop is being vested by his Church, the Priests, having received a blessing from the Bishop, go to the Vestry and vest.
See the link for a whole description. Here are some photos from St. Elias Church in Brampton, Ontario which shows their form of pontifical vesting.
All images courtesy of St. Elias Church.