Alter value of an ical field before importing feed

How can one modify the value of an ical field (in my case the Location field) before importing it?

I want to do this because the ical field is mapped to a taxonomy field in Drupal. The ics file is the following

BEGIN:VCALENDAR
VERSION:2.0
PRODID:shapes
BEGIN:VTIMEZONE
TZID:GTB Standard Time
BEGIN:STANDARD
DTSTART:20161002T040000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYHOUR=4;BYMINUTE=0;BYMONTH=10
TZNAME:GTB Standard Time
TZOFFSETFROM:+0300
TZOFFSETTO:+0200
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:20160301T030000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYHOUR=3;BYMINUTE=0;BYMONTH=3
TZNAME:GTB Daylight Time
TZOFFSETFROM:+0200
TZOFFSETTO:+0300
END:DAYLIGHT
END:VTIMEZONE
BEGIN:VEVENT
DESCRIPTION:
DTEND;VALUE=DATE:20170811
DTSTAMP:20170809T125455Z
DTSTART;VALUE=DATE:20170809
LOCATION:Building 11
SEQUENCE:0
SUMMARY:Morning
UID:96b6fe5b-4092-40f8-9ed3-76909bd2d778
END:VEVENT
END:VCALENDAR

What I want is, instead of LOCATION:Building 11, to have LOCATION:Room #11, because the terms on my taxonomy are of the form "Room #number".

I don't know if I'm thinking correctly about it but I should modify this part of date_ical.api.php? What would I have to add there?

/**
 * Alter the parsed data for an event imported from an iCal feed.
 *
 * @param array $data
 *   An associative array of field data that represents an imported event.
 * @param array $context
 *   An associative array of context, with the following keys and values:
 *   - 'calendar': The iCalcreator vcalendar parent object of this component.
 *   - 'source': FeedsSource object for this Feed.
 *   - 'fetcher_result': The FeedsFetcherResult object for this Feed.
 */
function hook_date_ical_import_post_parse_alter(&$data, $context) {
  // Example of what might be done with this alter hook.
  if (!empty($context['calendar']->xprop['X-WR-CALNAME']['value'])) {
    // Do something with the calendar name....
  }
}

I'd appreciate any help, thanks!