1. First download the texture pack in a .zip file format. Please ensure that the texture files/folders are in the main/root directory of the zip file itself. If you fail to follow that step, the texture pack will not work.
2. Once you have the zip file ready, simply host it somewhere such as with a web host or even on Dropbox. You will then want to have the direct URL to that file.
3. Once you have the direct URL, login to your Multicraft control panel.
4. Click files then config files then server settings.
5. Scroll down and find "texture-pack" (there will be a blank box next to it)
6. Enter in the URL to your texture pack file.
7. Click save at the bottom, then restart your server.
8. Now join your server and you should get a prompt to download the texture pack. You are done!