1) Read the LVL file specification about blocks settings:
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http://wohlsoft.ru/docs/LVL%20file%20description.pdf
2) Open level file in SMBX editor, and check the necessary block coordinates in debugger.
Warning, you must set it accurate, by left-up corner of block
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3) find necessary block in LVL file, using the coordinates information
and set number of need NPC:

0 - block is empty, 1-99 - block contains coins by 1 to 99, 1000+ - block contains NPC with ID= value-1000. I.e. if value=1056, block contains NPC-56.
NPC List in PDF: http://wohlsoft.ru/docs/NPC%20List.pdf
NPC List in ODS: http://wohlsoft.ru/docs/NPC%20List.ods
NPC List in XLS: http://wohlsoft.ru/docs/NPC%20List.xls
Result: (after saving LVL file via notepad, you must start level test without saving, or ReOpen same file in menu file/open):
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- Included Bowser:


Included big boo:

Video demonstration:
Original link: http://www.youtube.com/watch?v=c6X689qoJnA



