Inline the internal procedures deposit and withdraw. That is, replace references to them by the bodies of the procedures. Then you can eliminate the definitions of those procedures. How to turn the scheme code below into inline?
(define make-account-lambda
(lambda (balance)
(define withdraw (lambda (amount)
(if (>= balance amount)
(begin (set! balance (- balance amount))
balance)
"Insufficient funds")))
(define deposit (lambda (amount)
(set! balance (+ balance amount))
balance))
(lambda (m)
(cond ((eq? m 'withdraw) withdraw)
((eq? m 'deposit) deposit)
(else (error "Unknown request -- MAKE-ACCOUNT"
m))))))