I'm trying to modify uid with ldapmodify. This is my modify.ldif:
###---modify.ldif---###
dn: uid=old_user_uid,dc=dominio
changetype: modify
replace: uid
uid: new_user_uid

$ldapmodify -x -D "cn=admin,dc=dominio" -W -f modify.ldif
Enter LDAP Password:
modifying entry "uid=old_user_uid,dc=dominio"
ldap_modify: Naming violation (64)
additional info: value of naming attribute 'uid' is not present in entry

When I try to modify dn:
###---modify.ldif---###
dn: uid=old_user_uid,dc=dominio
changetype: modify
replace: dn
dn: uid=new_user_uid,dc=dominio

$ldapmodify -x -D "cn=admin,dc=dominio" -W -f modify.ldif
Enter LDAP Password:
modifying entry "uid=old_user_uid,dc=dominio"
ldap_modify: Undefined attribute type (17)
additional info: dn: attribute type undefined

I've seen RFC2849, and the examples have dn and uid fields like:

dn: cn=Gern Jensen, ou=Product Testing, dc=airius, dc=com
objectclass: top
objectclass: person
objectclass: organizationalPerson
cn: Gern Jensen
cn: Gern O Jensen
sn: Jensen
uid: gernj

Here is the output of #slapcat -a uid=old_user_uid
dn: uid=old_user_uid,dc=dominio
uid: old_user_uid
cn: SomeOne
homeDirectory: /home/old_user_uid
uidNumber: SomeNumber
objectClass: posixAccount
objectClass: shadowAccount
objectClass: person
objectClass: inetOrgPerson
gidNumber: SomeNumber
sn: Someone
shadowExpire: 14245
loginShell: /bin/bash
userPassword:: NWh0c0p0T3g=
shadowLastChange: 14193
structuralObjectClass: inetOrgPerson
entryUUID: 9a2b0c7a-488e-102d-8bce-7f1d632647aa
creatorsName: cn=admin,dc=dominio
createTimestamp: 20081117005833Z
entryCSN: 20081117013513Z#000000#00#000000
modifiersName: cn=admin,dc=dominio
modifyTimestamp: 20081117013513Z