How to Restore a Database pg_dump - Help - S.O.S.

I´m not DBA. I´m a infrastruture professional, please someone help me

In my company we have a PGSQL Linux Red Hat 9 Database
The relevant portions of my DB Backup Script follows
I can send too, the whole script with other parts of the code

The backup is beeing made with the ´bva´ parameters
How can i restore?
I have to do a su - postgresql?
i have to drop and recrate something?

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#!/bin/sh
#
# +-- Restoration can be performed by using psql or pg_restore.
# | Here are two examples:
# |
# | a) If the backup is plain text:
# |
# | Firstly gunzip your backup file (if it was gzipped).
# |
# | gunzip backup_file.gz
# | psql -U postgres database < backup_file
# |
# | b) If the backup is not plain text:
# |
# | Firstly gunzip your backup file (if it was gzipped).
# |
# | gunzip backup_file
# | pg_restore -d database -F {c|t} backup_file
# |
# | Note: {c|t} is the format the database was backed up as.
# |
# | pg_restore -d database -F t backup_file_tar
# |
# +-- Refer to the following url for more pg_restore help:
#
# http://www.postgresql.org/idocs/index.php?app-pgrestore.html
#

# Run backup, vacuum and analyze
run_bva() {
for i in $databases; do
start_time=`date '+%s'`
timeinfo=`date '+%T %x'`

"$location_binaries/vacuumdb" -z -h $postgresql_hostname -U $postgresql_username $i >/dev/null 2>&1
"$location_binaries/pg_dump" $backup_args -h $postgresql_hostname $i > "$location_backup_dir/`date +%B-%Y`/$date_info/$current_time-postgresql_database-$i-backup"
if [ "$backup_gzip" = "yes" ]; then
gzip "$location_backup_dir/`date +%B-%Y`/$date_info/$current_time-postgresql_database-$i-backup"
chmod $permissions_backup_file "$location_backup_dir/`date +%B-%Y`/$date_info/$current_time-postgresql_database-$i-backup.gz"
else
chmod $permissions_backup_file "$location_backup_dir/`date +%B-%Y`/$date_info/$current_time-postgresql_database-$i-backup"
fi
finish_time=`date '+%s'`
duration=`expr $finish_time - $start_time`
echo "Backup, Vacuum and Analyze complete (duration $duration seconds) at $timeinfo for schedule $current_time on database: $i, format: $backup_type" >> $location_logfile
done
exit 1
}

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