If you take off the armrest on the right side of your chair, it'll be easier to play your guitar.
If you remove the right armrest on your chair, you'll be able to move your arm more freely.
ーIf you take off the armrest on the right side of your chair, it'll be easier to play your guitar.
「椅子の右側の肘掛を取ったら、ギターを弾きやすいよ」
to take off で「取り外す」
armrest で「肘掛」
to play one's guitar で「ギターを弾く」
ーIf you remove the right armrest on your chair, you'll be able to move your arm more freely.
「椅子の右の肘掛を外したら、もっと自由に腕を動かせるようになるよ」
to remove で「外す」
to move one's arm more freely で「腕ももっと自由に動かす」
ご参考まで！
カナダ 
