Question About Log File Size When Alter Huge Table

I have the next question, and i would like to hear what do you think
about, and if is there a better solution for "my problem"

here is the question, I have a huge table with 60GB of data (image
files). The problem happen always when i try to ALTER the structure of
the table. For example I change a field char(3) to char(4)...the
sqlserver then performs the "alter table" command...that must be
something similar than "insert into the new table + drop the actual
table" and for that I need about 60GB o space for my LOG file, and
takes hours to complete the operation.

Is this the only way to alter a single field in my table??

I would like to heard you opinions...Thanks..

ALberto