easy
pain-free
unpainful
Mickey Mouse
casual
cinch
clear
comfortable
cushy
easy as pie
effortless
facile
glib
light
no sweat
nothing to it
plain
pushover
simple
simple as ABC
smooth
soft
straightforward
unburdensome
uncomplicated
painlessly
painlessness
benign
bloodless
conclusive
dreamless
expeditious
foolproof
illegible
impervious
inexpensive
innocuous
invulnerable
negligible
restful
unchanged
undamaged
undetectable
uneventful
uninterrupted
unreadable
untroubled
valueless
stainless
painful