The VG Resource

I am new to re-editing games, but I'm getting more and more into it. I do have a question I would like to ask. I would like to import graphics from different games to the game I am editing. I'm running into a problem with the sprites I want to import. They are much larger than the ones in the original game.  

For example, I am trying to replace the ship in Defender II with a sprite I created but it's too big (especially too tall to fit). In Defender II the ship takes up 3 blocks of 8, where as the one I want to import needs more. Do I need to go into the code and change a setting? If so how? If not can you please share any suggestions? Thanks again for the help!

Hopefully this made some kind of sense!

Thanks in advance!

Yeah, you need to go into ASM to change that, but this needs much knowledge to be able to do that.
Or find a workaround with the sprites.

Thanks for your help!