I think you have the wrong view on magick, true magick is a lot less like Hollywood makes it out to be. However, I just grabbed my book High Magick II from Frater U.D and on page 376 it says that
Glasya-Labolas has the power to teach all arts and sciences “in an instant” (information magic!)
If you do not have experience with evocation or invocation you could contact this entity through these means:
Or you can make contact with this method
(For optimal effects is best to use this method when doing either one of these below)
According to Vk Jehannum you can make contact with Glasya Labolas by visualizing this image, I just checked the book 'Lucifer and the Hidden Demons but I could not find Labolas in it. So this method can used instead or you can make contact by just visualizing the sigil/symbol you see here above the dog. 
Depiction of Glasya-Labolas by G.A. Rosenberg entitled Between Love and Bloodshed"
Or you can make contact with this method
Through basic goetic sigil magick
All these three methods can be amplified by playing any of these Glasya Labolas ritual songs. Maybe listen to a few and pick one that you resonate with the most 
*These are not my songs, the link directs to 'Glasya Labolas ritual music ’ search results on YouTube.
@Mulberry can I post this? because yesterday you removed a post of mine when I shared a link to a free baneful magick course that is hosted on Yt. You wrote that I’m not allowed to post anything on this forum unless I’m referring to my own experience with said practice. So I’m unsure if I’m allowed to help members by making these kinds of posts. i.e. directing them to posts that are listed on this very same forum.