Step 1: Train Your Right Hand First by doing Down Up strokes on all the Strings..
Step 2: Now Start your Left hand Exercises. This will take around 15 days to cover all the exercise with the speed of Minimum 100bpm..
I'll tell you the exercise of left hand.
Remember your 1st finger will be on first fret, 2nd on 2nd fret , 3rd on 3rd fret , 4th on 4th fret.
Exercise 1: 1234, Means you are going to play on 1st 2nd 3rd and 4th fret...
So just place your 1st finger on 1st fret and hit down stroke with your right hand , then place your 2nd finger on your 2nd fret and hit up stroke, then 3rd finger om 3rd fret and hit again down stroke and then 4th finger on your 4th fret and hit up stroke.
always remember you have to hit down up down up only.... Not Down down down down...
NOTE: If you are hiting only Down Down Down Down . this is the wrong technique ..and also try to stretch your Fingers.