You understand something wrong, *.map is the filetype you can open with the mohradiant to work,change... the map
*.pk3 is a form of zipped file, you can open pk3 with eg. winzip.
If you want to convert a existing map to a *.map file you had to use the *.bsp file which is zipped in the *.pk3
Although this map could be the 8? marvel in the world I think it is too much complicated to me. I need something easy to learn. I've read a lot of tutorial and I think I can do something but this is not enough... you know.... I have 1 thousand questions...
For example: Now I know that you can unzip the .pk3 file and obtain the *.bsp file, but radiant only can open .map, .reg and some files more... How I can obtain the .map from .bsp file???
You can convert the .bsp back into a .map but its as good as useless as it messes up all the brushes, it converts each face of a brush into a new single brush so you end with a with a crazy thing.
You can get the program that does it here
/files.php
its called MohaaTools
Philip II of Macedon sent a message to Sparta:
"If I win this war, you will be slaves forever."
The Spartan ephors sent back a one word reply: "If".