Hi! Sorry for the delay in responding, I'm currently unwell.
Make sure you unzip the zip folder to access the sprite sheets.
In the root of the main zip you'll find "Instructions for connections.png" which explains, visually, how the sprites match together. The assets are png sprite sheets, so can be used in any program you prefer (excluding anything related to the blockchain).
The sprites are non-square, so for unusual or specific uses you'll have to refer to the individual brick measurements in pixels by opening it in an image editor of your choice and measuring.
If you have further specific questions I'm happy to answer them here :~)