Alter Table Column

I have a column MYCOL of char(2) and I want to change it to char(10). This SQL does not work:

alter table MYSCHEMA.MYTABLE alter COLUMN MYCOL char(10);

What is the correct syntex?

Add column works fine:

alter table MYSCHEMA.MYTABLE add COLUMN MYCOL char(2);

Thanks!

I have manual "OpenEdge® Data Management:SQL Reference" but could not figure out the syntex.