Love your little Sam Monster. He is still very much a baby. If you practice
Cindy's 6 P's of Yorkie Training, then in time he will become a very obedient firkid....
1)
PRAISE- Use huge amounts of Praise -- in different levels -- Have very high value praise (maybe an irrestible treat) that Sam will work hard to get, have medium attention getting praise and lower level of praise -- the old "good boy" and scratch behind the ears.
2)
PATIENCE- Remember that Sam does not understand English, but he does "read" your body language. Be sure that your voice and body are telling him the same things and be patient if he "reads" you wrong. It could take several hundred repetitions of a behavior for him to fully understand what you are telling him -- remember the praise.
3)
PERSERVERANCE- Remember to keep on keeping on -- even when it seems like Sam will NEVER get it right. He is learning from you every single minute he can hear, smell or see you. Be sure what he is learning from you is positive.
4)
PERSISTANCE- Set a realistic training goal and stick with it. If the methods you are using don't seem to work (be sure to give them plenty of time), then don't be afraid to try a new method to teach the same lesson. But above all, DO NOT GIVE UP. Be Persistant.
5 & 6)
PEE and POOP-- Avoid both when possible. 
And please remember, that if your little one needs to relieve himself, it will be difficult for him to focus on learning.
Remember -- it is much easier for a dog to understand very specific commands than a geneneral one.