Handy gsub examples:

Removing the trailing % in the 5th field.

# echo "1 2 3 4 85%" | awk '/%/{gsub( /%/," ",$5); print}'
1 2 3 4 85
# echo "1 2 3 4 85%" | awk '/%/{gsub( /%/," ",$5); print $5}'
85
# echo "1 2 3 4 85%" | awk '/%/{gsub( /%/," ",$5); print $5","$2}'
85 ,2
# echo "1:2:3:4:85%" |  awk -F: '/%/{gsub( /%/," ",$5); print$5","$2}'
85 ,2

Need to remove white spaces?

# echo "1: 2 :3:4:5:6" | awk -F: '{print $2}'
 2 
# echo "1: 2 :3:4:5:6" | awk 'BEGIN{FS=OFS=":"}{gsub(/^[ \t]+/,"",$2);gsub(/[ \t]+$/,"",$2)}1'
1:2:3:4:5:6
# echo "1: 2 :3:4:5:6" | awk 'BEGIN{FS=OFS=":"}{gsub(/^[ \t]+/,"",$2);gsub(/[ \t]+$/,"",$2); print $2}'
2

Same as above but print specific fields.

This post was based on the following stockoverflow.com question:
http://stackoverflow.com/questions/20600982/remove-leading-and-trailing-space-in-field-in-awk