05AB1E, 99 bytes

ð¡3.$ðý ̈U"€ß€„ ".aX«ð«"€† "«TLΩ©«ð«"‡š›Ž"«®Θi ̈}'!«¶«¶«®F"Š\ "«N>«" - "«N>®QiX.a«ë"€·€– ".a«X«}'.«¶«

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 ¡ # split
 # implicit input
ð # by spaces
 3.$ # pop a, push a[3:]
 ý # pop a, join a
 ð # by spaces
 ̈ # pop a, push a[:-1]
 U # pop a, store a in X
 "€ß€„ ".a # push "How to "
 X« # concatenated with X
 « # concatenated with
 ð # a whitespace
 « # concatenated with
 "۠ " # "in "
 « # concatenated with
 Ω # a random element from
 L # [1, 2, ...,
 T # ..., 10]
 © # and store that in register_c
 « # concatenated with
 ð # a whitespace
 « # concatenated with
 "‡š›Ž" # "easy steps"
 i # if
 ® # the value in register_c
 Θ # is equal to 1
 ̈ # then pop a, push a[:-1]
  } # exit if statement
 « # concatenated with
 '! # an exclamation point
 « « # concatenated with (two chars)
 ¶ ¶ # two newlines
 F # for N in [0, 1, ...,
 ® # ..., register_c - 1]
 « # concatenated with
"Š\ " # "Step "
 « # concatenated with
 N> # N + 1
 " - "« # concatenated with " - "
 i # if
 N>  # N + 1
 Q # is equal to
 ® # the value in register_c
 « # then concatenated with
 X.a # X in Sentence case
 ë # else
 « # concatenated with
 "€·€– ".a # "Do not "
 X« # concatenated with X
 } # end if statement
 « # concatenated with
 '. # a period
« # concatenated with
 ¶ # a newline
 # implicit output

05AB1E, (削除) 99 (削除ここまで) 90 bytes

-9 bytes by using „ (two-char string) and ... (three-char string).

ð¡3.$ðý ̈U...€ß€„ .aX«ð«„€† «TLΩ©«ð«„‡š›Ž«®i ̈}...!
«®F„Š\ TM«N>«... - «N>®QiX.a«ë...€·€– .a«X«}„.
«

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