You can use PuTTY to telnet into your Dell PowerConnect 62xx switches to configure them and install new firmware. The CLI is much more powerful than the web interface of the 62xx series switches. This setup is not limited to stacking modules but in my example I am using multiple switches in a stack configuration so it only shows up as 1 switch in my configuration panel.

Download the Dell Switch Firmware from http://support.dell.com and enter the service tag of your switch to get the specific firmware for the model.

Download TFTP64server from here: http://tftpd32.jounin.net/tftpd32_download.html

Setup TFTP64server

Create a directory in C:\ root of your computer then make the following directories:

C:\switches\firmware  

Copy the dell firmware files to the firmware directory.
Commands for Telnet on 62xx switches:

Open Putty in Telnet mode to IP address of your Power Connect switch

THIS SYSTEM IS PROPERTY OF XXXXX COMPANY XXXXX INFORMATION TECHNOLOGY DEPARTMENT. UNAUTHORIZED USE OF THIS DEVICE IS NOT PERMITTED UNDER THE TERMS OF THE ACCEPTABLE USE POLICY.Press 'y' to continue (within 30 seconds) (y/n) y  
User:admin  
Password:*********  
SW-ENG>en  
SW-ENG#show version  
Image Descriptions  
image1 : default image  
image2 :

Images currently available on Flash  
--------------------------------------------------------------------
unit image1 image2 current-active next-active  
--------------------------------------------------------------------
1 3.2.0.7 3.2.1.3 image1 image1  
2 3.2.0.7 3.2.1.3 image1 image1  
SW-ENG#copy tftp://<yourTFTPserverIP>/<firmwareName>.stk imageMode...........................................  
TFTPSet TFTP Server IP............................. <yourTFTPserverIP>TFTP Path...................................... ./  
TFTP Filename.................................. <firmwareName>.stk  
Data Type...................................... Code  
Destination Filename........................... image

Management access will be blocked for the duration of the transferAre you sure you want to start? (y/n) y

TFTP code transfer starting9718796 bytes transferredFile reception completeVerifying file...File contents are valid.

Distributing the code to the members of the stack!File transfer operation completed successfully.

SW-ENG#show version

Image Descriptions  
image1 : default image  
image2 :

Images currently available on Flash  
--------------------------------------------------------------------
unit image1 image2 current-active next-active  
--------------------------------------------------------------------
1 3.2.0.7 3.3.4.1 image1 image1  
2 3.2.0.7 3.3.4.1 image1 image1

SW-ENG#boot system image2  
Activating image image2 ..  
SW-ENG#update bootcode  
Update bootcode and reset (Y/N)? Y

Issuing boot code update command...  

After hitting the 'Y' key on the Update bootcode and reset, the switch should be rebooted into the latest firmware. To confirm you can show version