There is only one button on the switch which you can press, the button is the mode button.

Press and hold then power on and off the switch until you reach switch:

switch: dir flash[0]:
unable to stat flash[0]:/: no such device

switch: dir flash
unable to stat flash/: no such device

switch:

without initializing the flash you cannot list the flash directory.

switch: flash_init
Initializing Flash...
flashfs[0]: 420 files, 8 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 15998976
flashfs[0]: Bytes used: 15049728
flashfs[0]: Bytes available: 949248
flashfs[0]: flashfs fsck took 11 seconds.
...done Initializing Flash.

switch:

Use the command flash_init as highlighted above.

switch: dir flash:
Directory of flash:/

  512  drwx  192                      c3750-ipservicesk9-mz.122-50.SE1
  456  -rwx  1876                     vlan.dat
  425  -rwx  2072                     multiple-fs
  458  -rwx  16445                    running-config
  424  -rwx  24                       private-config.text
  426  -rwx  16517                    config.text

949248 bytes available (15049728 bytes used)

switch:

Rename config.text or delete it.

switch: delete flash:config.text
Are you sure you want to delete "flash:config.text" (y/n)?y
File "flash:config.text" deleted

switch:

Normally you should rename the config.text to another filename like config.old, but because this switch belongs to me now and i do not care about previous config. However you should do the right thing, so to rename the file you do this.

switch: dir flash:
Directory of flash:/

2    -rwx  15174     <date>               running-config
3    -rwx  1921      <date>               private-config.text
4    -rwx  1784      <date>               vlan.dat
511  drwx  192       <date>               c3750-ipservicesk9-mz.122-40.SE
509  -rwx  15841     <date>               config.text
510  -rwx  1048      <date>               multiple-fs

switch: rename flash:config.text flash:config.old

switch: dir flash:
Directory of flash:/

2    -rwx  15174     <date>               running-config
3    -rwx  1921      <date>               private-config.text
4    -rwx  1784      <date>               vlan.dat
511  drwx  192       <date>               c3750-ipservicesk9-mz.122-40.SE
509  -rwx  15841     <date>               config.old
510  -rwx  1048      <date>               multiple-fs

3533824 bytes available (12465152 bytes used)

switch:

Boot the IOS.

switch: boot
Loading "flash:c3750-ipservicesk9-mz.122-50.SE1/c3750-ipservicesk9-mz.122-50.SE1.bin"...

When the IOS has booted successfully you should see something like this:

         --- System Configuration Dialog ---

Enable secret warning
----------------------------------
In order to access the device manager, an enable secret is required
If you enter the initial configuration dialog, you will be prompted for the enable secret
If you choose not to enter the intial configuration dialog, or if you exit setup without setting the enable secret,
please set an enable secret using the following CLI in configuration mode-
enable secret 0
----------------------------------
Would you like to enter the initial configuration dialog? [yes/no]: no
Switch>en
Switch#conf t

now do what you need, like rename the config.old to config.text and do the enable password and save it…

Switch#rename flash:config.old flash:config.text
Destination filename [config.text]?
Switch#copy flash:config.text run
Switch#conf t
Switch(config)#enable secret cisco
Switch(config)#do wr
Building configuration...
[OK]
Switch(config)#