Monday, Tuesday and Wednesday in Holy Week are privileged ferias. No feast may take precedence over them. A feast is either commemorated or transferred depending on its rank.
On Monday at the Hours the antiphons are proper. Mattins has one nocturn. At the second scheme of Lauds the ferial preces are sung, the choir kneeling. The ferial preces are also sung at the Hours again, the choir kneeling. At Mass the second collect is Ecclesiae, for the Church, the preface is of the Cross, there is an Oratio super populum and the dismissal is Benedicamus Domino. Vespers are ferial with preces feriales sung kneeling and at Compline the preces are also sung kneeling.
On Tuesday all is similar to Monday. The notable exception is that as on Palm Sunday a Passion is sung at Mass. On Tuesday this is the Passion according to St. Mark. The same ceremonies as mentioned on Palm Sunday apply.
On Wednesday again a similar pattern is followed. At Prime in the Martyrology the first announcement is that of Maundy Thursday. After today the Martyrology is not read until Holy Pascha. At Mass there are two lessons from Isiah before the Passion and Gospel. The Passion according to St. Luke is sung.
On the evening of Spy Wednesday, Wednesday in Holy Week, Mattins and Lauds is sung in a special form known as Tenebrae.
In the 'liturgical books of 1962' following the 'Restored' order of Holy Week dalmatic and tunicle are worn by the deacon and subdeacon rather than folded chasubles. No commemorations are allowed and there is no second collect in the Masses. Any text read by a lector, subdeacon or deacon is not read by the celebrant (extended throughout the year in the 1962 books). OHSI of 1955 orders the Orate fratres to be said in an audible voice and all to respond. Ferial preces are sung only on Wednesdays at Lauds and Vespers only. The Passions are shortened somewhat and the Gospel ceremonies omitted.
The second relevant installment by Signor Gregory Di Pippo on the 'restoration' may be found here.