First off
If you want to change your body you have to change your diet and your training.
The advice I am going to give you is the same advice I have been given it is nothing fancy just simple but it works. The most important elements to diet and training is constancy as Sassy has already mentioned.
Diet:
To maintain your current weight you need to eat about 1300 calories a day. This number comes from your current weight x 12. I find when building muscle the best diet break down is 40% protein 30% complex carbs 30% fat.
Training:
NO CARDIO! With you current build you don't need it is just going to hinder muscle growth.
Weights
You can do a split 3 to 5 days whatever works for your schedule.
Compound movements (i.e squat, bench, deadlift) rep range 6-8 sets 4
Isolated movements rep range 10-15.
You need to make sure you are lifting heavy that means by the second set your last rep you should be feeling muscle fatigue and your last set the last 2 reps will seem almost impossible to do.
This is an example of my split
Chest & Biceps
BB Bench Press 4 sets 6-8 reps
BB Curls 4 sets 6-8 reps
DB Incline press 4 sets 8-12 reps
DB hammer curls 4 sets 8-12 reps
Standing Cable Fly 4 sets 8-12 reps
Cable curl 4 sets 8-12 reps
Back & Hamstrings
BB SL Deadlifts 4 sets 6-8 reps
BB Deadlifts 4 sets 6-8 reps
BB Goodmornings 4 sets 8-12 reps
BB Bent over rows 4 sets 8-12
Lying Leg Curl 4 sets 8-12 reps
Pulldowns 4 sets 8-12 reps
Shoulders & Triceps
DB Shoulder Press 4 sets 6-8 reps
BB Lying tricep extensions 4 sets 6-8 reps
Rear Lat raise 4 sets 8-12 reps
Tricep pushdown 4 sets 8-12 reps
Upright Rows 4 sets 8-12 reps
Dips 4 sets 8-12 reps
Quads & Calfs
BB Squat 4 sets 6-8 reps
Standing calf 4 sets 10-15 reps
Hack Squats 4 set 10-15 reps
Seated Calf raise 4 sets 10-15 reps
Plie squats 4 sets 10-15 reps
*Abs every work out
Hanging legs raises 4 sets 8-12 reps
Crunches 4-5 sets 20-25 reps
Side crunches 4-5 sets 20-25 reps each side
Happy lifting