The Monastic Office for the Feast of SS Philip and Mark is unfortunately not available on Divinum Officium, but most of the texts are from the Office from the Common of Apostles and Evangelists in Eastertide.
Accordingly, you can find most of the relevant texts - except the readings and twelfth responsory - in the Liber Responsorialis (which can be downloaded for free from the CC Watershed Library).
The Invitatory antiphon (Regem Apostolorum Dominum), hymn (Tristes erant apostoli), psalms and antiphons are from the Common, (starts page 162) or elsewhere in the book (page numbers are given in the Common).
The readings and responsories can be found on my Lectio Divina Blog (and sources for chants for the responsories can be found here.
Accordingly, you can find most of the relevant texts - except the readings and twelfth responsory - in the Liber Responsorialis (which can be downloaded for free from the CC Watershed Library).
The Invitatory antiphon (Regem Apostolorum Dominum), hymn (Tristes erant apostoli), psalms and antiphons are from the Common, (starts page 162) or elsewhere in the book (page numbers are given in the Common).
The readings and responsories can be found on my Lectio Divina Blog (and sources for chants for the responsories can be found here.
