Install button is currently not available. You have to do it manually copying and pasting the below code in your tumblr.

• Show Pages! (Deactivate infinite scroll on your customize page theme on tumblr)
• Display or hide Title!
• Upload Cursor!
• All themes are customizable, you can change background, link color, text color etc.
• You can edit the theme all what you want as long as you leave the credit.
• Do NOT remove credit or your theme will NOT work!
• This theme has the infinity scrolling page