Thank you for your short response Leo.

The problem is that I tried to do it with a TFTP server but wasnt able to establish connection between my pc and the AP.

I've converted APs before, but never an air-CAP3702i-a-k9.

I will try to convert but havent been succesful so far.

Thanks again

The problem is that I tried to do it with a TFTP server but wasnt able to establish connection between my pc and the AP.

What error messages are you getting?  Is the PC firewall turned off?

The firewall is off.

I'm using 3CDaemon and the message that I get is that it cant open the file.

I tried using the following filenames: ap3g2-k9w7-tar.default and ap3g2-k9w7-tar.153-3.JC by CLI in the WLC.

Do you know what can I be doing wrong or another walkaround for this issue?

I'm using 3CDaemon and the message that I get is that it cant open the file.

Are you sure this is the error message?  

Run the entire proceedure again and post the entire process.  I want to see everything, including the error message. 

Attached is the capture in the TFTP Server.

I then tried the second method (Using MODE Button and TFTP Server) and still couldnt do it. In this case, the problem was the following:

IOS Bootloader - Starting system.
flash is writable
Tide XL MB - 40MB of flash
Xmodem file system is available.
flashfs[0]: 68 files, 9 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 41158656
flashfs[0]: Bytes used: 20953600
flashfs[0]: Bytes available: 20205056
flashfs[0]: flashfs fsck took 11 seconds.
Base Ethernet MAC address: 00:42:68:18:22:30
Ethernet speed is 1000 Mb - FULL Duplex
button is pressed, wait for button to be released...
button pressed for 24 seconds
process_config_recovery: set IP address and config to default 10.0.0.1
process_config_recovery: image recovery
image_recovery: Download default IOS tar image tftp://255.255.255.255/ap3g2-k9w7-tar.default

examining image...
DPAA Set for Independent Mode
tide_boot_speed = 1000
DPAA_INIT = 0x0

%Error opening tftp://255.255.255.255/ap3g2-k9w7-tar.default (permission denied)ap:

What do you think that can be wrong?

permission denied

"permission denied". That says a lot. Check the "permission" of the file. 

If not, try using another computer to be the TFTP server.

Do you think the problem is the TFTP Server or the computer?

Thank you

I am suspecting the computer is the problem.