Clarifying and comparing methods of renewing visa

I know this subject gets beat to death so I apologize for any redundancy here but I'm getting down to the wire on deciding whether I'm going oto (1) let an agency help me with renewing my TP7, or (2) Do it myself.

I know that letting the agency do it is probably foolproof... but it cost more money. I also understand that many people have successfully completed the process themseles through the online option (Cancelleria....whatever).

I'm the guy that had some help doing the online process last year and had some delays and glitches and wound up not getting a renewed Cedula (in Barranquilla).

Now, based on some information I've gotten from helpful forum members here, I understand that I should not have that Cedula problem if I try it again. But...

Now I'm trying to visualize how I would get my new visa, i.e. the one that's glued into my passport. I remember that last year I sent my passport, with Power of Attorney, to a lady-friend of mine in Bogota and she took it down to Immigration in Bogota and got my new visa glued into it. So...

Do I have to do that again?

I don't want the hassle and expense of going to Bogota so if I use the online process...how does my new visa get into my passport? Or do they send it to me and I glue it in myslef. Or does Migration here in Medellin do it? Or can I courier my passport to Immigration.....or what?

I'm just looking for the cheapest way to get it done.

Thanks in Advance,
Art

p.s. I'm glad this next visa should be for 3 years instead of one. One year goes by pretty fast.