Initial situation:

 #################
##     #   #     #
#####  #     K O #
#   ##### I## # ##
# A ##   # ## M  #
#  C  DG # ##LNP #
## ###   # ##    #
 # #   ### #####R#
## #     H  #....#
# B### ## J #....##
# @   E #   #..Q. #
#  ## F #  ##.... #
#####   ######...##
    #####    #####

Move past E, push it out of the way.

 #################
##     #   #     #
#####  #     K O #
#   ##### I## # ##
# A ##   # ## M  #
#  C  DG # ##LNP #
## ###   # ##    #
 # #   ### #####R#
## #     H  #....#
# B### ## J #....##
#    E@ #   #..Q. #
#  ## F #  ##.... #
#####   ######...##
    #####    #####

Push F left, Move H somewhere more convenient, move J a bit, too.

 #################
##     #   #     #
#####  #     K O #
#   ##### I## # ##
# A ##   # ## M  #
#  C  DG # ##LNP #
## ###   # ##    #
 # #   ### #####R#
## #        #....#
# B### ##@  #....##
#    E  #J  #..Q. #
#  ##FH #  ##.... #
#####   ######...##
    #####    #####

Push I down and left, push K left and down, push O left.

 #################
##     #   #     #
#####  # O@      #
#   #####  ## # ##
# A ##   # ## M  #
#  C  DG # ##LNP #
## ###   # ##    #
 # #   ### #####R#
## # I      #....#
# B### ## K #....##
#    E  #J  #..Q. #
#  ##FH #  ##.... #
#####   ######...##
    #####    #####

Finish Q and R (not sure about correct placement for finishing the
stones, figure it out yourself ;).

 #################
##     #   #     #
#####  # O       #
#   #####  ## # ##
# A ##   # ## M  #
#  C  DG # ##LNP #
## ###   # ##    #
 # #   ### #####@#
## # I      #....#
# B### ## K #....##
#    E  #J  #R... #
#  ##FH #  ##Q... #
#####   ######...##
    #####    #####

Push L up, push P down, push L left.

 #################
##     #   #     #
#####  # O    @L #
#   #####  ## # ##
# A ##   # ## M  #
#  C  DG # ## N  #
## ###   # ##  P #
 # #   ### ##### #
## # I      #....#
# B### ## K #....##
#    E  #J  #R... #
#  ##FH #  ##Q... #
#####   ######...##
    #####    #####

Finish P, N, M, L, O, K, I, J, H, G, D, C, A, B, E, F.