Shift Linkage Problem 2008 Chevy Aveo LS Manual 5Speed

My clutch has been freshly replaced. Clutch is smooth.However, I sometimes have problem while shifting to 1st and 2nd gear. 3rd 4th and 5th are smooth. Most of the times, all gears shift good. I noticed the gear lever is slightly tilted towards right side. I asked the mechanic about it. He says "its a new clutch it becomes smooth after riding for a while". I suspect there is a problem with shift linkage. How do I replace it? Do I need to remove the transmission? Can it be replaced from the top side of engine bay?
Recent cluch replacement cost me huge so I don't wanna spend more. I would like to do it myself and learn.
Please help.

-Release parking brake, depress the clutch, put transmission in 1st gear, and rev the engine. If your car moves any bit, the clutch is not fully disengaging. That could be a hydraulic issue or spacing issue
-Check trans fluid. Low fluid can cause issues
-Trans synchros can be worn out

Sorry for getting back to you so late. Shift linkage needed some asjustment. Got it fixed finally.