Where can I find a translation of the poem "The Upcheringe of the Messe" by Luke Shepherd?

There's no "translation" of Luke Shepherd's poem "The Upcheringe of the Messe" because it's already in English! So why does the poem look so strange and sometimes indecipherable? Because it is not written in modern English! 
Luke Shepherd is a pen name derived from two religious references: "Luke" referring to the "Luke" of the Gospels and "Shepherd" referring to the biblical herders of sheep. The writer known as Luke Shepherd was penning his satirical religious works during the mid 16th century under the reign of Edward VI; this time period marked the gradual shift from Middle English to Early Modern English. While can be difficult to understand Early Modern English (which was used for Shakespeare's works, the King James Bible, etc.),  reading pieces like "The Upcheringe of the Messe" (which might be best classified as "Renaissance verse") is certainly not impossible for a contemporary reader.  
So, how should we approach this process? When reading "The Upcheringe of the Messe," you must attempt to look past the odd spelling of words and think phonetically instead. This becomes less difficult with practice. For example, look at a few lines from the early part of the poem:

"Wherin the high professours
Apostlique successours
Take holde to be possessours
And some wer made confessours
Some of them were no startars
But were made holi marters..."

When we start to look closely, we can "translate" this into modern English:

Wherein the high professors [in other words, one who "professes"]
Apostolic successors [one who inherits something; in this case a position or title]
Take hold to be possessors 
And some were confessors
Some of them were no starters
But were made holy martyrs...

Shepherd is essentially critiquing those in positions of power within the Church as being title-hungry. He is also criticizing the false worship of these figures, who are often seen as being holy and self-sacrificial.
See how we can start to decipher the words that look "wrong" to us by saying them out loud and paying attention to vowel sounds rather than spellings? 
Another tool that should prove to be helpful for you is the University of Michigan's Middle English Dictionary, which is an online database that allows you to look up tricky words that you may not be able to understand. I have included the link below. 
https://quod.lib.umich.edu/m/middle-english-dictionary/dictionary