delete the white spaces

Hello y have one xml with this:
<root>hola soy yo</root>
i make:
<xsl:value-of select="root" disable-output-escaping="yes"/>
but it shows me the white spaces.
how can i:

1.- delete the whie spaces and show:
holasoyyo

2.- how can i substitute the whiel spaces with %20?
hola%20soy%20yo


thanks