true to play slowly is the key at first, if you cant play ata tempo that allows mistakes you have to slow down!,but practice small parts on the horn, ie D,E, F# and get to know little" passages then expand them,heres an exersise, in the key of D".
D,E,F#..X 2.. D,E,F#,G,A...X2...D,E,F#,G,A,B,C#...2..and so on until you have gone up one or two octaves,if you stumble on technique go back and start again, dont settle for complacency make it right.
keep the fingers close to the keys, and yes sat on the pearls, not half an inch or so off them,the fingers should be close to the keys, if not touching almost watch the pros", and you will see what i mean, you dont see many with a wild technique!!..
play different rhythms quarter notes eight notes, and hkeep your foot tapping for accuracy, metronomes are very useful too..
good luck