Import this module to that wiki (or copy the code over, giving attribution in the edit summary). Give the module a name that makes sense in that wiki's language (hereafter referred to as MODULENAME)
Create a template (which should probably have the same name as the module, but referred to here as TEMPLATENAME) containing the code <includeonly>{{#invoke:MODULENAME|main}}</includeonly><noinclude>{{TEMPLATENAME|demo=yes}}{{Documentation}}</noinclude>
Localise the module. Edit the top bits of the module, between the comments -- ##### Localisation (L10n) settings ##### and -- #### End of L10n settings ####, replacing values between "" symbols with local values (as necessary)
Create the categories defined in the module localisation. These should be made hidden categories, either by including a Template:Hidden category (Q5879327) template, or by directly including the __HIDDENCAT__magic word.
Add documentation to the template (e.g. by translating Template:Attached KML/doc, adjusting as necessary per any localisations made in the previous step) and to the module (please transfer/translate these instructions so that wikimedians who read your wiki but not the English Wikipedia can also set up the module and template on another wiki).
