no problem, always here to help
if you want to change your texture/picture for an object because you dont like it, just go to the object which you want to change the texture, just go to the objects attribute editor and click on checked box instead of assigning a new material.
also a tip here, if you want two objects to have the same material, the one without the texture/picture just right click on the object and go,
go to Materials
assign excisting material and find the object's name you want to copy off. if you have trouble just post in here again and i will help out